Do you have to pick one? cause if so i'd say diagrams and headings
A prepositional phrase contains a preposition and usually a noun. Your answer would be the first choice.
example:
I went over the hill. "Over the hill" is a prepositional phrase.
Answer:
The correct inference: one of the requirements to be accepted into the nursing program is 20+ hours of health-care-related volunteer work.
Explanation:
I find it interesting that you asked for the correct inference instead of the answer to the question it is asking (revision of the paragraph).... I hope this is truly what you needed. If not, I can edit this answer
C running away from the palace in the middle of the night