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
[{'content': "All are cavitating lesions in the lungs, except? \nSelect and explain. \nA. Caplan's syndrome, B. Hamaoma, C. Wegner's granuloma, D. Squamous cell carcinoma", 'role': 'user'}, {'content': "Answer: B \nExplanation: Answer is B (Hamaoma): Hamaomas produce non cavitating popcorn calcifications. Malignant lesions (squamous cell carcinoma) and granulomatous lesions (Wegener's granulomatosis, Caplan's syndrome) are established causes of cavitatory lesions.", 'role': 'assistant'}]