Is exquisite old painting a prepositional phrase

No

Explanation:

A prepositional phrase relates a noun to another word. Exquisite and old are both adjectives but not prepositions. Prepositions include below, before, over, past, from, etc.

answer; (b); the abolitionist movement;

whatever is after like is what is being compared they are comparing bumping into you like they are scared to catch germs you have and to you being contagious