This MS-900 practice question tests your understanding of describe microsoft 365 apps and services. 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.
An organization uses Microsoft 365 E5 and wants to implement a solution that automatically detects and remediates security incidents across identities, endpoints, and email. Which Microsoft 365 service should they use?
Microsoft Defender XDR
Defender XDR correlates signals across identities, endpoints, email, and more to detect and remediate incidents.
Microsoft Defender for Endpoint
Why wrong: This focuses on endpoints only.
Microsoft Sentinel
Why wrong: Sentinel is a SIEM/SOAR, not a built-in XDR solution.
Microsoft Entra ID Protection
Why wrong: This focuses on identity risks, not cross-domain incidents.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Microsoft Defender XDR
Microsoft Defender XDR (Extended Detection and Response) is the correct choice because it provides a unified, cross-domain security solution that automatically correlates alerts and orchestrates remediation across identities, endpoints, email, and cloud apps. This aligns directly with the requirement to detect and remediate security incidents across identities, endpoints, and email, leveraging the Microsoft 365 Defender portal to break down silos between individual security products.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Microsoft Defender XDR
Why this is correct
Defender XDR correlates signals across identities, endpoints, email, and more to detect and remediate incidents.
Related concept
Read the scenario before looking for a memorised answer.
Microsoft Defender for Endpoint
Why it's wrong here
This focuses on endpoints only.
Microsoft Sentinel
Why it's wrong here
Sentinel is a SIEM/SOAR, not a built-in XDR solution.
Microsoft Entra ID Protection
Why it's wrong here
This focuses on identity risks, not cross-domain incidents.
Common exam traps
The trap here is that candidates often confuse Microsoft Defender XDR with its individual component products (like Defender for Endpoint or Defender for Office 365), mistakenly assuming that a single-domain solution can meet a cross-domain requirement, or they overestimate Microsoft Sentinel's out-of-the-box automation capabilities versus its actual SIEM-centric, custom-playbook nature.
Detailed technical explanation
Under the hood, Microsoft Defender XDR uses a shared data lake and advanced machine learning models to fuse signals from Defender for Endpoint, Defender for Office 365, Defender for Identity, and Microsoft Entra ID Protection into a single incident graph. This enables automatic containment actions—such as isolating a compromised device, blocking a malicious email sender, or revoking a compromised user session—without requiring manual SIEM querying or custom playbook development. In a real-world scenario, if a phishing email triggers a credential theft alert on a user's mailbox and that same user's device later shows suspicious process behavior, Defender XDR automatically merges these into one incident and applies coordinated remediation across both email and endpoint.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
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.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Describe Microsoft 365 apps and services — study guide chapter
Learn the concepts, then practise the questions
Describe Microsoft 365 apps and services practice questions
Targeted practice on this topic area only
All MS-900 questions
985 questions across all exam domains
Microsoft 365 Fundamentals MS-900 study guide
Full concept coverage aligned to exam objectives
MS-900 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise MS-900 questions linked to Describe Microsoft 365 apps and services.
Practise MS-900 questions linked to Describe Microsoft 365 pricing, licensing, and support.
Practise MS-900 questions linked to Describe cloud concepts.
Practise MS-900 questions linked to Describe security, compliance, privacy, and trust in Microsoft 365.
Practise MS-900 questions linked to Describe Microsoft 365 pricing and support.
Practise MS-900 questions linked to MS-900 fundamentals.
Practise MS-900 questions linked to MS-900 scenario.
Practise MS-900 questions linked to MS-900 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Describe Microsoft 365 apps and services — This question tests Describe Microsoft 365 apps and services — Read the scenario before looking for a memorised answer..
The correct answer is: Microsoft Defender XDR — Microsoft Defender XDR (Extended Detection and Response) is the correct choice because it provides a unified, cross-domain security solution that automatically correlates alerts and orchestrates remediation across identities, endpoints, email, and cloud apps. This aligns directly with the requirement to detect and remediate security incidents across identities, endpoints, and email, leveraging the Microsoft 365 Defender portal to break down silos between individual security products.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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 →
Last reviewed: Jun 24, 2026
This MS-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 MS-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.