Answer: It (C) because dinosaurs wasn't present during that period time so
answer choice (a) isn't accurate and doesn't make any sense to platonic plates and (d) us talking about height which it doesn't matter because it not answering the questions
I know I already answer the question for you but the fact that this question is easy and your saying it hard you probably didn't know what platonic plates are so this is the reasoning behind the answer if you trying to figure out why that is the answer
I hope this helps :)