Answer the following question given this paragraph: 

The jejunum is the second part of the small intestine. This is where most nutrients are absorbed into the blood. The inside surface of the jejunum is covered with tiny projections called villi (villus, singular). The villi make the inner surface of the small intestine 1000 times greater than it would be without them. You can read in Figure below how villi are involved in absorption.


Q: The inside surface of the jejunum is covered with tiny projections called what?

 Choices:

- flagella

- mucosa

- alveoli

- villi

A:
villi
