- A
The sample file is automatically selected as the first file in alphabetical order.
Why wrong: The sample file is the first file that Power Query reads, which may not be alphabetical.
- B
Only the sample file is imported; other files are ignored.
Why wrong: All files are imported; the sample file is just a template for transformations.
- C
The combine process uses Power Automate to merge files.
Why wrong: The combine is done entirely within Power Query without external services.
- D
Power Query creates a function that applies the same transformations to each file.
An auto-generated function is used to process each file using the sample file's steps.
- E
Power Query creates a sample file query that serves as a template for all files.
The sample file query defines the transformations that are applied to every file.
PL-300 Prepare the data Practice Question
This PL-300 practice question tests your understanding of prepare the data. 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.
You are importing data from a folder containing multiple CSV files with identical structure. You use the 'Combine files' transform in Power Query. Which TWO statements are true about this process?
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
Power Query creates a function that applies the same transformations to each file.
Option D is correct because when you use the 'Combine files' transform in Power Query, it automatically generates a function that applies the same transformations (e.g., promoting headers, changing data types) to each CSV file in the folder. This function is invoked for every file, ensuring consistent data shaping across all files.
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.
- ✗
The sample file is automatically selected as the first file in alphabetical order.
Why it's wrong here
The sample file is the first file that Power Query reads, which may not be alphabetical.
- ✗
Only the sample file is imported; other files are ignored.
Why it's wrong here
All files are imported; the sample file is just a template for transformations.
- ✗
The combine process uses Power Automate to merge files.
Why it's wrong here
The combine is done entirely within Power Query without external services.
- ✓
Power Query creates a function that applies the same transformations to each file.
Why this is correct
An auto-generated function is used to process each file using the sample file's steps.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Power Query creates a sample file query that serves as a template for all files.
Why this is correct
The sample file query defines the transformations that are applied to every file.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse the 'sample file' as being the only file imported (Option B) or think the process uses an external tool like Power Automate (Option C), when in reality Power Query handles the entire merge natively with a generated function.
Detailed technical explanation
How to think about this question
Under the hood, Power Query creates a 'Sample File' query that defines the transformation steps (e.g., Table.PromoteHeaders, Table.TransformColumnTypes) and a 'Transform File from Example' function that applies these steps to each file. The function uses parameters like 'Parameter1' for the file binary content, and Power Query iterates through all files in the folder using Table.Combine to merge the results. A subtle behavior is that if the sample file has a different structure (e.g., extra columns), the function may fail for other files, so it's critical to ensure the sample file is representative.
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 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
Got this wrong? Here's your next step.
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FAQ
Questions learners often ask
What does this PL-300 question test?
Prepare the data — This question tests Prepare the data — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Power Query creates a function that applies the same transformations to each file. — Option D is correct because when you use the 'Combine files' transform in Power Query, it automatically generates a function that applies the same transformations (e.g., promoting headers, changing data types) to each CSV file in the folder. This function is invoked for every file, ensuring consistent data shaping across all files.
What should I do if I get this PL-300 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
This PL-300 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 PL-300 exam.
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