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: Anatomy
[{'content': 'Muscle that causes flexion at elbow joint when forearm is semi - pronated \nSelect and explain. \nA. Biceps brachii, B. Brachialis, C. Coracobrachialis, D. Brachioradialis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Brachioradialis causes flexion at elbow joint when forearm is semi - pronated.', 'role': 'assistant'}]