Answer:
Option B
The plicae circulares, villi, and microvilli
Step-by-step explanation:
The plicae circulares are the folds of mucous membrane on the inside of the small intestine. They are covered with tiny hair-like structures called the villi, and microvilli. The purpose of those folds is to increase the surface area for the absorption of food nutrients to take place in the small intestine before the food finally moves on to the large intestine for excretion.
The tiny hair-like projections (villi, and microvilli) further increase the surface area available for nutrient absorption by providing extra surfaces in which the nutrients can diffuse into the small intestine through.
This makes option B correct.