What Are the Functions of the Sinuses

Multiple Choice

What are the functions of the sinuses?

A) to drain fluid from the brain and to allow the brain to expand
B) to give a resonant sound to the voice and to allow the brain to expand
C) to lighten the skull and drain fluid from the brain
D) to lighten the skull and give a resonant sound to the voice
E) to allow the brain to expand and to lighten the skull