Asthma is a respiratory disease concerned with

Name the chronic respiratory disorder caused mainly by cigarette smoking in which alveolar walls are damaged.

If a person stays on Mount Everest for some days,what will happen to their red blood cells (RBCs)?

$A$ chronic disorder in which alveolar walls are damaged due to excessive cigarette smoking is

Assertion $(A):$ $A$ person goes to high altitude and experiences 'altitude sickness' with symptoms like breathing difficulty and heart palpitations.
Reason $(R):$ Due to low atmospheric pressure at high altitude,the body does not get sufficient oxygen.
In the light of the above statements,choose the correct answer from the options given below.

Emphysema is a chronic disorder caused by which of the following?