Answer:
The correct option is : b. Bronchiole smooth muscle contracts which reduces the diameter of the airways
Explanation:
Asthma is an incurable inflammatory disease which affects the airways that carry the oxygen in and out of the lungs. It can be caused by various genetic and environmental factors. Asthma is characterized by breath shortness, coughing, chest tightness and wheezing.
It is caused due to the inflammation of the passage that conducts air into the lungs, especially the bronchi and the bronchioles. Asthma does not affect the alveoli. The inflammation of the bronchioles causes the contraction of the smooth muscles and results in narrowing of the airways. Therefore, causing wheezing.
