Answer:
Particulate matter in the inhaled air is trapped by the <u><em>epithelial mucus.</em></u>
Explanation:
The complete question is:
<em>"Particulate matter in the inhaled air is trapped by the __________.
</em>
<em>a. tracheal carina
</em>
<em>b. paranasal sinuses
</em>
<em>c. pharyngeal muscles
</em>
<em>d. epithelial mucus"</em>
The nostril is covered with a mucous membrane that, at its highest part, is formed by an epithelium that contains cells that produce mucus and hair cells covered with fine hairs, called vibratil cilia. Epithelial cells help protect against the entry of microorganisms. In other words, certain types of epithelial cells have tiny hairs called cilia, which help remove foreign substances.
So, <u><em>particulate matter in the inhaled air is trapped by the epithelial mucus.</em></u>
