This GCDL practice question tests your understanding of google cloud products, services, and solutions. 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.
A developer needs to grant a service account the minimum permissions required to publish messages to a Pub/Sub topic. Which IAM role should they assign?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "minimum / minimize"
Why it matters: Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
roles/editor
Why wrong: Broad role that grants many permissions, including Pub/Sub admin, overkill.
roles/pubsub.subscriber
Why wrong: Grants permission to subscribe and pull messages, not publish.
roles/pubsub.publisher
Grants only the permission to publish messages to the topic.
roles/pubsub.admin
Why wrong: Grants full control over all Pub/Sub resources, exceeding the minimum.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
roles/pubsub.publisher
The correct answer is C because the `roles/pubsub.publisher` role grants the minimum permissions required to publish messages to a Pub/Sub topic. This role includes the `pubsub.topics.publish` permission, which allows a service account to send messages to a specific topic without granting any other unnecessary permissions like subscribing or managing the topic.
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.
roles/editor
Why it's wrong here
Broad role that grants many permissions, including Pub/Sub admin, overkill.
roles/pubsub.subscriber
Why it's wrong here
Grants permission to subscribe and pull messages, not publish.
roles/pubsub.publisher
Why this is correct
Grants only the permission to publish messages to the topic.
Clue confirmation
The clue word "minimum / minimize" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
roles/pubsub.admin
Why it's wrong here
Grants full control over all Pub/Sub resources, exceeding the minimum.
Common exam traps
Google Cloud often tests the distinction between publisher and subscriber roles, and the trap here is that candidates may confuse `roles/pubsub.publisher` with `roles/pubsub.subscriber` or assume a broad role like `roles/editor` is acceptable, overlooking the principle of least privilege.
Detailed technical explanation
Under the hood, the `pubsub.topics.publish` permission is checked by the Pub/Sub service when a client sends a `publish` request via the gRPC or REST API. The publisher role is scoped at the project or topic level, and using a custom role with only this permission is even more granular. In a real-world scenario, a CI/CD pipeline service account that only needs to push event notifications to a topic should be assigned `roles/pubsub.publisher` to follow the principle of least privilege and avoid accidental subscription or topic management.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Google Cloud products, services, and solutions — study guide chapter
Learn the concepts, then practise the questions
Google Cloud products, services, and solutions practice questions
Targeted practice on this topic area only
All GCDL questions
507 questions across all exam domains
Google Cloud Digital Leader study guide
Full concept coverage aligned to exam objectives
GCDL 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 GCDL questions linked to Why cloud technology is transforming business.
Practise GCDL questions linked to Fundamental cloud concepts.
Practise GCDL questions linked to Google Cloud products, services, and solutions.
Practise GCDL questions linked to Scaling with Google Cloud operations.
Practise GCDL questions linked to Trust and security with Google Cloud.
Practise GCDL questions linked to GCDL fundamentals.
Practise GCDL questions linked to GCDL scenario.
Practise GCDL questions linked to GCDL troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Google Cloud products, services, and solutions — This question tests Google Cloud products, services, and solutions — Read the scenario before looking for a memorised answer..
The correct answer is: roles/pubsub.publisher — The correct answer is C because the `roles/pubsub.publisher` role grants the minimum permissions required to publish messages to a Pub/Sub topic. This role includes the `pubsub.topics.publish` permission, which allows a service account to send messages to a specific topic without granting any other unnecessary permissions like subscribing or managing the topic.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "minimum / minimize". Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
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 →
Keep practising
Last reviewed: Jun 30, 2026
This GCDL practice question is part of Courseiva's free Google Cloud 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 GCDL 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.