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
[{'content': 'Fraying of anterior ends of ribs is seen in \nSelect and explain. \nA. Scurvy, B. Rickets, C. Down syndrome, D. Osteoporosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Rickets', 'role': 'assistant'}]