An asthma attack, in which breathing becomes difficult with wheezing, is caused by
- A. fluid filling the alveoli
- B. constriction of the bronchi and bronchioles with excess mucus
- C. destruction of the cartilage rings of the trachea
- D. paralysis of the diaphragm
Explanation
The airway smooth muscle contracts and the lining swells with mucus, narrowing the tubes so air whistles through. Inhalers relax the muscle, confirming that constriction, not destruction, is the problem.
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