no right answers; or perhaps two?
The question in the POST is can I explain the answer. Well, yes and no--the right answer is either doubled or MISSING! Bad question (typical bureaucratic incompetence).
But to amplify Nick (wow, how presumptuous of me!),
The problem is semantic: where is the pitch INcreasing or DEcreasing--that is, where is it CHANGING (note that the answers do not address "where is it greatest" or "where is it least").
And thus two answers are semantically correct: for during the advancing 180 degrees of travel, the pitch decreases then increases; and then during the retreating 180 degrees, pitch increases then decreases.
If we had a correct answer inluded in the choices, it would say "the pitch is greatest somewhere on the retreating side and least somewhere on the advancing side." [Thanks, Frank Robinson, for generating many long discussions of fine-tuning evasion as to exactly where . . .]
Would Nick pass the exam? I suspect so--but for the wrong reasons--he (and many of us) are accustomed to reading between the lines and evaluating what the question-writer had in mind (that obvious lack-of-conceptual-awareness) and choosing the answer the bureaucrat expected. Which is technically wrong, but they don't consider the implications of their wording!
Now what we need to do is form a committee of informed pilots to be so honored by the test-making agencies as to carefully weed out and reword questions like this that are patently unanswerable but the gummint fails to notice or care!