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: Medicine
[{'content': 'Which is the most common site of subcutaneous nodules in rheumatoid arthritis - \nSelect and explain. \nA. Elbow, B. Wrist, C. Achilles tendon, D. Occiput', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]