This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Primary ossification centre of all bones of lower limb forms by \nSelect and explain. \nA. 8 weeks, B. 10 weeks, C. 12 weeks, D. 14 weeks', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Primary ossification centre of all bones of lower limb forms by 12 weeks', 'role': 'assistant'}]