Mammalian lungs have an enormous number of minute alveoli (air sacs). This is to allow

Options

A. more surface area for difusion of gases
B. more space for increasing the volume of inspired air
C. more nerve supply to keep the lungs working
D. more spongy texture for keeping lung in proper shape.

Answer

A

Explanation

The numbe of alveoli in the human lungs has been estimated to be approximately `300` million. This cnormous number of alveoli are meant to increase surface area of lungs for diffusion of gases.