Question 322 of 505
Infrastructure and AutomationeasyMultiple ChoiceObjective-mapped

200-901 Infrastructure and Automation Practice Question

This 200-901 practice question tests your understanding of infrastructure and automation. 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.

{
    "response": [
        {
            "hostname": "Core-Router",
            "managementIpAddress": "10.1.1.1",
            "platformId": "ISR4451-X",
            "serialNumber": "F0C1234A5B6",
            "lastUpdated": "2023-11-28T15:30:00.000+00:00"
        }
    ],
    "version": "2.0.0"
}

A developer uses the Cisco DNA Center API to retrieve device inventory. The JSON response is shown. Which Python code snippet correctly extracts the serial number?

Exhibit

Refer to the exhibit.

{
    "response": [
        {
            "hostname": "Core-Router",
            "managementIpAddress": "10.1.1.1",
            "platformId": "ISR4451-X",
            "serialNumber": "F0C1234A5B6",
            "lastUpdated": "2023-11-28T15:30:00.000+00:00"
        }
    ],
    "version": "2.0.0"
}

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

data['response'][0]['serialNumber']

Option A is correct because the JSON response from the Cisco DNA Center device inventory API returns a list of devices under the 'response' key, and each device is a dictionary. The serial number for the first device is accessed by indexing into the list with [0] and then retrieving the 'serialNumber' key from that dictionary.

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.

  • data['response'][0]['serialNumber']

    Why this is correct

    Correctly accesses first element.

    Related concept

    Read the scenario before looking for a memorised answer.

  • data['serialNumber']

    Why it's wrong here

    Missing 'response' array access.

  • data['response']['serialNumber']

    Why it's wrong here

    response is a list, not dict.

  • data[0]['serialNumber']

    Why it's wrong here

    Index 0 at top level doesn't exist.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates mistakenly treat the JSON response as a flat dictionary or forget that the 'response' value is a list, leading them to omit the list index and incorrectly access 'serialNumber' directly from 'response'.

Detailed technical explanation

How to think about this question

The Cisco DNA Center API returns paginated results where the 'response' key contains a list of device objects, each with fields like 'serialNumber', 'hostname', and 'managementIpAddress'. Accessing the serial number requires navigating the nested structure: first the 'response' key, then the list index (e.g., [0] for the first device), and finally the 'serialNumber' key. In real-world scenarios, you would often iterate over the list to process multiple devices, not just the first one.

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 practitioner preparing for the 200-901 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

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FAQ

Questions learners often ask

What does this 200-901 question test?

Infrastructure and Automation — This question tests Infrastructure and Automation — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: data['response'][0]['serialNumber'] — Option A is correct because the JSON response from the Cisco DNA Center device inventory API returns a list of devices under the 'response' key, and each device is a dictionary. The serial number for the first device is accessed by indexing into the list with [0] and then retrieving the 'serialNumber' key from that dictionary.

What should I do if I get this 200-901 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.

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Last reviewed: Jun 24, 2026

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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.