A disease caused by gradual breakdown of the thin walls of alveoli is:

Explanation

Option A, tuberculosis, is a bacterial infection of the lungs, characterized by persistent cough, fever, and weight loss. This involves granuloma formation and cavitation of the lung tissue so, it is not the disease described in the question. Option B, asthma, is the thickening of the bronchioles due to an excessive allergic reaction upon exposure to certain agents and irritants (allergens). Option C, emphysema, is the correct answer, as it involves the breakdown of the alveolar elastic tissue resulting in the breakdown of alveolar walls, leading to the formation of large pockets within the lungs. Option D, bronchitis, is a chronic disease, that involves excessive mucus production in response to prolonged smoking.