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: Orthopaedics
[{'content': 'Posterolateral Anconeus triangle is formed by all, except \nSelect and explain. \nA. Head of the radius, B. Medical epicondyl, C. Lateral epicondyl, D. Olecrenon', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]