This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Smoking is generally not associated as a risk factor with - 
Select and explain. 
A. Small cell carcinoma, B. Respiratory bronchiolitis, C. Emphysema, D. Bronchiolitis obliterans organizing pneumonia
D: Bronchiolitis obliterans organizing pneumonia
Answer: D: Bronchiolitis obliterans organizing pneumonia 
Explanation: None