What is Reddit's opinion of AWS Certified Developer Associate Practice Tests [2022]: 390 AWS Practice Exam Questions with Answers & detailed Explanations?

From 3.5 billion Reddit comments

Or here's another one I found today from this book: https://smile.amazon.com/gp/product/B08B563TN7

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>An application scans a DDB once per day during non-peak hours when production uses about 50% of allocated throughput. How can you MINIMIZE the time it takes to produce the report without affecting production workloads (pick 2)
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>1. Use a parallel scan
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>2. Increase Read Capacity Units during the scan operation
>
>3. Use the limit parameter

Obviously, 1 is correct, but the answer key said that the other correct answer is 3 because 2 would increase costs. 3 would prevent you from using all of the RCUs during the scan. Throttling the operation won't minimize the time it takes, and optimizing for cost wasn't included as a requirement.

So this answer is flagrantly wrong! Should I expect to have to second-guess things like this in the test? Where I'm expected to optimize for metrics that aren't specified, sometimes at the expense of metrics that are?