Answer : 1. "Protects lungs"
Explanation :

Answer: A) Protects lungs Explanation: When you breathe in air through your nose, it contains lots of tiny things, like dust, dirt, germs, and pollen. The air enters our body through the nose. However, before it enters the lungs, it must be heated and purified. Many dust particles that enter along with the air are removed in the nose by mucus and thus it protects lungs.