This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bone and Imaging, Subject name: Orthopaedics
[{'content': 'Radial head ossifies at the age of: \nSelect and explain. \nA. 2 years, B. 4 years, C. 6 years, D. 10 years', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ossifications around elbow Mn: C R I T O E C- Capitulum -2 years R- Radial head - 4 years I- Inner/medial epicondyle - 6 years T- Trochlea - 8 years O- Olecranon -10 years E- External/lateral epicondyle - 12 years', 'role': 'assistant'}]