Well, I'm not familiar on what your answer choices are because you haven't provided them, however I'll give you a few tips on what proves a cell is prokaryote
-The absence of a nucleus proves a cell is a prokaryote
-Prokaryotes lack an organized nucleus and other membrane-bound organelles
-The cell wall of a prokaryote acts as an extra layer of protection, helps maintain cell shape, and prevents dehydration.
So these are just a few couple of helpful tips- see your answers and if any of these sound similar there is your answer! Good luck.