Which of these best explains why the small intestine is called the small intestine?

A
It is 1 inch wide.

B
It is 20 feet long.

C
It is where digestion finishes.

D
It is lined with microscopic villi.

B

It is 20 feet long.

The main reason why the small intestine is called the "small" intestine is because of its length, which is typically around 20 feet long in adults.