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: Radiology
Causes of a cavitating lesion in the chest radiograph are all except - 
Select and explain. 
A. Hamartoma, B. Pulmonary infarction, C. Squamous carcinoma of the bronchus, D. Caplan's syndrome
A: Hamartoma
Answer: A: Hamartoma 
Explanation: Haematoma (not hamartoma) causes lung cavitation.
Pulmonary infarct, squamous cell carcinoma of lung, RA & Caplan's syndrome can also cause lung cavitation.