Philosophy of X is how we talk about X, the terminology and the state of our understanding. Philosophy is a huge part of learning, but we usually don't call it philosophy.

That would make sense if there was a freeform "why did you give this answer" section. As a multiple-choice question, there's nothing you can infer about the answer.

Or maybe it was a control question and the teacher is going to treat the spread of results as their own little survey...