The answer is Azure Blob Storage trigger and Azure Event Grid. These two services are correct because Azure Functions natively supports a Blob Storage trigger that monitors a container for new blobs and executes your function code upon creation, while Event Grid offers a more scalable, event-driven alternative by subscribing to the 'Microsoft.Storage.BlobCreated' event for low-latency HTTP-based invocation. On the AZ-204 exam, this distinction tests your understanding of serverless integration patterns—the Blob Storage trigger is simpler but can suffer from latency under high throughput, whereas Event Grid is preferred for real-time, high-volume scenarios. A common trap is confusing the Blob Storage trigger with Event Grid’s blob created event, but remember: the Blob Storage trigger polls the storage account, while Event Grid pushes events instantly. For the exam, think "poll vs. push" to differentiate them. Memory tip: "Blob polls, Grid pushes."
AZ-204 Develop for Azure storage Practice Question
This AZ-204 practice question tests your understanding of develop for azure storage. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
Which TWO Azure services can be used to trigger an Azure Function when a new blob is created in a storage account? (Choose two.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Azure Event Grid trigger
Option C is correct because Azure Event Grid provides a native event-driven integration that can trigger an Azure Function when a new blob is created. By subscribing to the 'Microsoft.Storage.BlobCreated' event, Event Grid delivers low-latency, reliable HTTP-based events directly to the function, making it ideal for high-throughput, serverless workflows.
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.
✗
Azure Cosmos DB trigger
Why it's wrong here
Cosmos DB trigger works with Cosmos DB change feed.
✗
Azure Queue Storage trigger
Why it's wrong here
Queue trigger responds to queue messages, not blob creation.
✓
Azure Event Grid trigger
Why this is correct
Event Grid can route blob creation events to a function.
Related concept
Read the scenario before looking for a memorised answer.
✓
Azure Blob Storage trigger
Why this is correct
Blob Storage trigger fires when a new blob is detected.
Related concept
Read the scenario before looking for a memorised answer.
✗
Azure Service Bus trigger
Why it's wrong here
Service Bus trigger works with queues/topics, not blob events.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often assume the Blob Storage trigger is the only native option, forgetting that Event Grid is also a first-class trigger for blob creation events and is actually the recommended approach for low-latency scenarios.
Detailed technical explanation
How to think about this question
Under the hood, the Azure Blob Storage trigger uses a polling mechanism that scans for new blobs in a container, which can introduce latency of up to several minutes depending on the function app's scale and the container's size. In contrast, Event Grid pushes events with sub-second latency via HTTP webhooks, and it supports advanced filtering (e.g., by blob name prefix/suffix) to reduce unnecessary invocations. A real-world scenario where this matters is processing high-volume image uploads: Event Grid ensures near-instant processing, while the Blob Storage trigger might miss blobs if the function app is scaled to zero during idle periods.
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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this AZ-204 question in full detail.
Develop for Azure storage — This question tests Develop for Azure storage — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Azure Event Grid trigger — Option C is correct because Azure Event Grid provides a native event-driven integration that can trigger an Azure Function when a new blob is created. By subscribing to the 'Microsoft.Storage.BlobCreated' event, Event Grid delivers low-latency, reliable HTTP-based events directly to the function, making it ideal for high-throughput, serverless workflows.
What should I do if I get this AZ-204 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 →
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 AZ-204 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 AZ-204 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.