It is called the Rugae.
Rugae is a term used in anatomy to refer to a series of ridges produced by folding of the wall of an organ. For example the gastric rugae which allows for expansion of the stomach after the consumption of foods and drinks. The rugae of the vagina are the transverse ridges on the mucous membrane lining the vagina. They allow the vagina to stretch during childbirth.
In a cladogram, when does a group of organisms branch off? when a new trait evolves when an ancestor becomes extinct when it is discovered when it becomes large enough
B-monomer
I am not sure about the second one but i think it's C
