The answer is D) enzymes.
“Enzymes are protein catalysts. A specific region of an enzyme where a substrate binds and catalysis takes place.”
"The gradual and long-term removal of fine-grated particles like dust and sand, leaving behind bigger fragments".
Is it the theory of evolution or “Lamarckism”
Because the lung has two bronchi, it can still function if one bronchus is blocked by a foreign object. No gas exchange will happen to the affected side, and the other lung will compensate for the loss of air. The blocked portion though can become inflamed and can lead to infection and damage.
