Yep, that's definitely the thought process the question-asker intended. I'm sidestepping that slightly: if an answer is chosen completely at random then one should be able to completely ignore the text of the question and answer, and roll a four-sided die, leading to 25%. I agree that strategy assumes that there's a single correct answer. And the typical expectation of a multiple choice question is to only have a single correct answer. The question itself says "the answer" not "answer(s)", that's perhaps a partial support of the expectation of a single correct answer. But yes, my assumption that there's only a single correct answer, while reasonable in general, could be considered flawed considering the nature of the question itself.