Another delegation question

I was taking a practice exam and the general gist of the question was in a situation where only one of these could be delegated, what should be delegated to UAP: vital signs, patient hygiene or Q2 turns (in addition to another one that was easily wrong). I picked Q2 turns because it seemed like you would do assessing while providing hygiene care or taking vitals- but it was supposed be providing hygiene care. Anyone have an explanation because all three of those things are things that CAN be delegated to UAP, and all three provide patient interaction that the RN could use for assessing , so why was that one the best?

I don't know why I have such trouble with delegation questions, even after reading the review materials. Thanks for any insight.