The answer is the top 10 high-severity alert titles ranked by the number of distinct affected devices. This is correct because the Kusto query filters for high-severity alerts, then uses the summarize operator to group by AlertTitle while applying dcount(DeviceName) to count unique devices per alert, followed by order by descending on that count and take 10 to return only the highest-ranked results. On the SC-900 exam, this tests your ability to interpret Advanced Hunting queries in Microsoft Defender XDR, specifically how summarize with dcount differs from count, which is a common trap—count tallies all rows, while dcount counts unique values. A helpful memory tip: think “dcount = distinct count,” and remember that the query’s final take 10 ensures you see only the top offenders, not all alerts.
SC-900 Practice Question: Describe the capabilities of Microsoft security solutions
This SC-900 practice question tests your understanding of describe the capabilities of microsoft security solutions. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Exhibit
Refer to the exhibit.
```kusto
DeviceAlertEvents
| where Timestamp > ago(7d)
| where AlertSeverity == "High"
| summarize Count = dcount(DeviceName) by AlertTitle
| top 10 by Count
```
Refer to the exhibit. You run a Kusto query in Microsoft Defender XDR Advanced Hunting. What does this query return?
Refer to the exhibit.
```kusto
DeviceAlertEvents
| where Timestamp > ago(7d)
| where AlertSeverity == "High"
| summarize Count = dcount(DeviceName) by AlertTitle
| top 10 by Count
```
A
Top 10 high-severity alert titles by number of distinct affected devices
Query uses dcount on DeviceName for high-severity alerts.
B
Top 10 alert titles by number of distinct devices, including all severities
Why wrong: Filtered to high-severity only.
C
Top 10 devices with the most high-severity alerts
Why wrong: Summarizes by AlertTitle, not DeviceName.
D
Top 10 high-severity alert titles by total number of alerts
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Top 10 high-severity alert titles by number of distinct affected devices
The query filters for high-severity alerts, then summarizes by AlertTitle and counts distinct DeviceName values. It orders by that count descending and takes the top 10, so it returns the top 10 high-severity alert titles ranked by the number of distinct affected devices.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Top 10 high-severity alert titles by number of distinct affected devices
Why this is correct
Query uses dcount on DeviceName for high-severity alerts.
Related concept
Read the scenario before looking for a memorised answer.
✗
Top 10 alert titles by number of distinct devices, including all severities
Why it's wrong here
Filtered to high-severity only.
✗
Top 10 devices with the most high-severity alerts
Why it's wrong here
Summarizes by AlertTitle, not DeviceName.
✗
Top 10 high-severity alert titles by total number of alerts
Why it's wrong here
Uses dcount, not count.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse 'distinct devices' with 'total alerts' or 'devices with the most alerts', and overlook the explicit severity filter, leading them to choose options that ignore the high-severity filter or misidentify the aggregation column.
Detailed technical explanation
How to think about this question
The Kusto query uses the `summarize` operator with `dcount(DeviceName)` to estimate the number of distinct devices per alert title, which is efficient for large datasets. The `order by` clause sorts by the distinct device count in descending order, and `take 10` limits the result set. This is a common pattern in advanced hunting to identify which alert types are spreading across the most endpoints, aiding in prioritization of response efforts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this SC-900 question in full detail.
Describe the capabilities of Microsoft security solutions — This question tests Describe the capabilities of Microsoft security solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Top 10 high-severity alert titles by number of distinct affected devices — The query filters for high-severity alerts, then summarizes by AlertTitle and counts distinct DeviceName values. It orders by that count descending and takes the top 10, so it returns the top 10 high-severity alert titles ranked by the number of distinct affected devices.
What should I do if I get this SC-900 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Refer to the exhibit. You run an Advanced Hunting query in Microsoft Defender XDR. What is the primary purpose of this query?
hard
A.Find IP addresses with failed logon attempts.
B.List all interactive logons from Office 365 applications.
C.Detect non-interactive logons to Office 365.
✓ D.Identify accounts with high number of interactive logons, potentially indicating brute-force activity.
Why D: The query filters for interactive logon events to Office 365 over the past 7 days, groups by user and IP, and counts occurrences. It then filters for accounts with more than 10 logon events, which helps identify accounts with unusually high logon activity, potentially indicating brute-force attacks or compromised accounts. Option A is correct.
Last reviewed: Jun 24, 2026
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This SC-900 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SC-900 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.