**Core Concept**
Interstitial lung disease (ILD) encompasses a group of disorders characterized by inflammation, fibrosis, and scarring of the lung interstitium, leading to impaired gas exchange and respiratory symptoms. ILD can be idiopathic or associated with various underlying conditions, including connective tissue diseases, inhalation exposures, and drug toxicity.

**Why the Correct Answer is Right**
Among the given conditions, sarcoidosis is the one with the least common association with interstitial lung disease. Sarcoidosis is a systemic granulomatous disease that primarily affects the lungs, but it can also involve other organs such as the skin, eyes, and lymph nodes. While pulmonary involvement is common in sarcoidosis, the disease typically presents with lymphangitic carcinomatosis-like patterns or nodular infiltrates rather than classical interstitial lung disease. The correct answer is associated with a condition that is more commonly linked with interstitial lung disease, making it the least common option.

**Why Each Wrong Option is Incorrect**
**Option A:** Idiopathic pulmonary fibrosis (IPF) is a classic example of a condition that presents with interstitial lung disease, characterized by a progressive decline in lung function due to fibrosis.

**Option B:** Connective tissue diseases, such as systemic lupus erythematosus (SLE), are well-known to be associated with interstitial lung disease, which can range from mild to severe.

**Option C:** Asbestosis is a classic occupational lung disease that results from asbestos exposure, leading to interstitial lung disease characterized by fibrosis and scarring.

**Clinical Pearl / High-Yield Fact**
ILD can be idiopathic or secondary to various underlying conditions, and a thorough history and physical examination are essential in differentiating between these causes.

**Correct Answer:** C.