Which of the following is/are true about ‘Villi’?
I. They are present in the walls of the small intestine.
II. They contain numerous blood vessels which take the absorbed food to every cell of the body.
III. They increase the surface area for absorption.

The inner lining of the small intestine has numerous finger-like projections called Villi. It increases the surface area for absorption in the small intestines. The villi are richly supplied with blood vessels which take the absorbed food to each and every cell of the body, where it is utilised for obtaining energy, building up new tissues and the repair of old tissues. The unabsorbed food is sent into the large intestine where more villi absorb water from this material. Hence, option D is correct.