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: Unknown
[{'content': 'For a distended knee joint which of the following position is most comfortable ? \nSelect and explain. \nA. Full extension, B. 30° flexion, C. 60° flexion, D. 90° flexion', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In 30° flexion, knee joint has maximum capacity and pressure of contained fluid or blood is minimum and consequently there is least pain. Capacity of knee joint decreases and pain thereby increases when the knee is fully extended or flexed more than 30°-45°.', 'role': 'assistant'}]