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.
Answer:
The correct answer will be option a and b.
Explanation:
The food is digested and absorbed in the small intestine, a long folded tube which lengths about 20 ft or 6m.
The small intestine increases the surface area for food absorption as they have circular folding as well as the finger-like projections called villi and microvilli in the lumen of the intestine. These villi help in absorption of the nutrients from the intestine.
Thus, option a and b are the correct options.