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: Pathology
[{'content': 'Erlenmeyer flask deformity of bones is seen in? \nSelect and explain. \nA. Achondroplasia, B. Osteopetrosis, C. Osteogenesis Imperfecta, D. Pagets disease', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Due to deficient osteoclast activity bones lack medullary canal and the ends become bulbous giving rise to Erlenmeyer flask deformity.', 'role': 'assistant'}]