**Core Concept**
The patient's presentation suggests a chronic respiratory condition exacerbated by smoking, with a recent change in sputum color and increased symptoms. This scenario points towards a specific type of lung disease characterized by chronic inflammation, airway obstruction, and potentially, respiratory infections.

**Why the Correct Answer is Right**
The patient's history of smoking, chronic productive cough, and recent change in sputum color are indicative of chronic bronchitis, a subtype of chronic obstructive pulmonary disease (COPD). Chronic bronchitis is characterized by chronic inflammation of the bronchial tubes, leading to excessive mucus production and recurrent infections. The greenish color of the sputum is likely due to the presence of pus, indicating a bacterial infection. The coarse rhonchi and wheezes heard on examination are consistent with airway obstruction.

**Why Each Wrong Option is Incorrect**
**Option A:** While asthma can cause wheezes and cough, it is less likely in this case due to the patient's age, smoking history, and chronic productive cough, which are more characteristic of COPD.

**Option B:** Pneumonia is a possibility given the patient's fever and productive cough, but the chronic nature of the symptoms and the lack of acute onset make this less likely.

**Option C:** Bronchiectasis is a condition characterized by irreversible dilation of the bronchi, often resulting from recurrent infections. While it can cause chronic productive cough, the patient's smoking history and acute symptoms suggest a more straightforward diagnosis of COPD.

**Option D:** This option is not provided.

**Clinical Pearl / High-Yield Fact**
Chronic bronchitis is a major risk factor for developing lung cancer, particularly in smokers. The patient's history of smoking and chronic productive cough should prompt a discussion about lung cancer screening.

**Correct Answer:** C.