This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Joint disorders, Subject name: Orthopaedics
[{'content': "Heberden's nodes are seen in: \nSelect and explain. \nA. Osteoahritis of the Distal interphalangeal joints, B. Osteoahritis of the Proximal interphalangeal joints, C. Rheumatoid ahritis of the 1st carpometacarpal joint, D. Rheumatoid ahritis of the Distal interphalangeal joints", 'role': 'user'}, {'content': "Answer: A \nExplanation: Osteoahritis characteristically involves distal interphalangeal joint (Heberden's node), proximal interphalangeal joint (Bouchard's node), 1st carpometacarpal joint (base of thumb) of hand with sparing of metacarpophalangeal joint and wrist joint.", 'role': 'assistant'}]