Which structure of the respiratory system moistens and filters inhaled air?
a. pharynx
b. bronchioles
c. nasal cavity
d. trachea

The correct answer is -

C. nasal cavity.

Explanation:

Nasal cavity is the part of upper respiratory tract that makes the air warm and humid when the air passed through it. It is done with the help of mucous and cilia that are located within nasal cavity, which trap the air particles so as to prevent any damage in the delicate tissues of the Respiratory System.

Thus, option c) is the right answer.

answer; ///i believe the correct answer is (aids) acquired immune deficiency syndrome;

layer 3 is younger than layer 6.