This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2017, Subject name: Orthopaedics
[{'content': "Herberden's ahropathy affects: \nSelect and explain. \nA. Lumbar spine, B. Sacroiliac joint, C. Distal interphalangeal joint, D. Knee joint", 'role': 'user'}, {'content': "Answer: C \nExplanation: Osteoahritis of DIP is known as Heberden's nodes. Osteoahritis of PIP is known as Bouchard's nodes Sacroiliac joint is affected in ankylosing spondylitis Knee joint is usually affected in osteoahritis &Pseudogout", 'role': 'assistant'}]