Suppose you are looking at a scene that has mountains near an a ocean. where do you think the crust would be the thickest? why?

The mountains are the thickest. They are thickest because, in the sea, the surface of the crust caves in, making it thinner. The mountains make the surface pop up. Pretend you're digging in the dirt, the hole represents the sea, and the pile of dirt represents the mountain.