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: Surgery
[{'content': 'The commonest cause of pathological fracture is generalized affection is: \nSelect and explain. \nA. Carcinoma, B. Osteoporosis, C. Cyst, D. All of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Ostoporosis', 'role': 'assistant'}]