**Core Concept**
Wool-sorter's disease, also known as Byssinosis, is an occupational respiratory disease caused by inhaling cotton dust, particularly in textile mills. The condition is characterized by narrowing of the airways and symptoms similar to asthma.

**Why the Correct Answer is Right**
The pathophysiology of Wool-sorter's disease involves the inhalation of cotton dust, which triggers a hypersensitivity reaction in the airways. The cotton dust contains spores of fungi, such as *Aspergillus*, and other particles that irritate the mucous membranes and cause inflammation. The condition is mediated by the release of histamine and other chemical mediators, leading to bronchoconstriction and airway obstruction. The symptoms of Wool-sorter's disease can be relieved by removing the patient from the source of exposure and administering bronchodilators.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe Wool-sorter's disease. While it is a respiratory condition, it is not caused by exposure to silica dust.
**Option B:** This option is incorrect because it is a different occupational respiratory disease caused by exposure to asbestos fibers.
**Option C:** This option is incorrect because it is a type of lung cancer associated with smoking and asbestos exposure.

**Clinical Pearl / High-Yield Fact**
Wool-sorter's disease is often referred to as the "brown lung disease" due to the brown discoloration of the lungs seen on chest X-ray.

**Correct Answer:** D. Byssinosis