Answer:
The correct answer is option B. dirtier.
Explanation:
Air inhaled through the mouth would be dirtier than air inhaled through the nose. The layer of the mucous membrane of the nasal cavity assists the nose to filter the air and moist it. This membrane helps in trapping dirt and other particles and prevents to get in the lungs.
Whereas inhaling through the mouth it is not the case filter is not present however it provides moisture and warmth but as much as the nose provides.
Thus, the correct answer is option B. dirtier.
