This question is very-poorly worded and confusing especially with the sentence in parentheses added at the end. Maybe it should have been something more like:
Where should you click in order to add a new animation?
The words ‘start’ adding’ lend to some confusion in addition to the sentence following, leading the quiz-taker in thinking that there should be some sort of click/dragging motion involved.
Was this an actual Unity Certification test question?