200-901 Understanding and Using APIs Practice Question
Which TWO HTTP methods are considered safe (idempotent and without side effects on the server)?
⚠ Common exam trap
Cisco often tests the distinction between idempotent and safe, trapping candidates who assume that idempotent methods (like PUT and DELETE) are also safe, when in fact safety requires no side effects on the server, which PUT and DELETE clearly violate.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
HEAD
(HEAD) is correct because the HEAD method is defined as idempotent and safe per RFC 7231: it retrieves the same headers as a GET request but without a response body, causing no side effects on the server. Option E (GET) is also correct because GET is explicitly defined as a safe method that only retrieves data and does not modify server state, making it idempotent.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
POST
Why it's wrong here
POST is not idempotent and may create resources.
- ✗
PUT
Why it's wrong here
PUT is idempotent but modifies resources, not safe.
- ✓
HEAD
Why this is correct
HEAD is identical to GET but returns only headers; safe.
- ✗
DELETE
Why it's wrong here
DELETE is idempotent but modifies resources.
- ✓
GET
Why this is correct
GET is safe and idempotent.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-901 practice question is part of Courseiva's free Cisco 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 200-901 exam.