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': "The first sign of Volkman's ischemia is - \nSelect and explain. \nA. Paresthesia, B. Pain on passive extension of fingers, C. Pain on active extension of fingers, D. Swelling of fingers", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Stretch pain is the earliest sign of impending compartment syndrome. The ischemic muscles, when stretched, give rise to pain.', 'role': 'assistant'}]