Enthuware

The comment for the right answer is "Generally, it is preferable to list specific permissions instead of giving a blank check except is certain situations."
How would I know that this is one of the "certain situations"? Wouldn't it be safer to provide just the actual permission required, as stated in option A?

is there any hint in the security guideline that talks about these exceptional cases?

The key term here is "build manager" or "administrator" or similar. If you see that you can select AllPermissions.