Which structure's primary function is to warm and moisten the air?
a. nasal cavity
b. epiglottis
c. bronchus
d. bronchiole

a. nasal cavity

Explanation:

The nasal cavity is a external opening of the respiratory tract. This involves two canal like cavities through which air enters the respiratory tract and moves out of the body. These are the two hollow spaces within the nose each of which consists of mucus and lined up with the hairs.

The primary function of the two nasal cavities is to moisturize, warm and filter the air entering the respiratory tract. These cavities filter out environmental contaminants like dust, pollen, molds and others.

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

your answer is c! hope this : )