Sorry, I mis-read the question

Are you sure the key has it as true. This exact question was #18 on the Part 1 test last year and I answered it false and got it correct.

Furthermore, I don't believe a person is reading too much into this by answering it false. There's a big difference between "during the down" and "end of the kick". For example, R88 is blocking gunner K87 when the punter kicks a high short punt to the sideline. Seeing this, R88 releases K87 and calls for a fair catch. Perfectly legal and the person who gave the FC signal blocked "during the down".

How about instead it's a poorly worded question where the intent by the author was to make it true?
That, in my humble opinion, is constantly a problem with the NFHS tests. There are a number of questions where you have to read "intent" into what they are getting at rather than just evaluating the question. For example, the already much discussed #2.
But I also don't worry about it too much, because even with missing the f'd up questions, it's possible to pass the test. You guys don't have to score 100%, do you? It's better to known how the ruling goes on the field than in the fairy land of the NFHS test and it seems most here have that down.