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: Surgery
[{'content': 'Blood clot the size of a clenched first is roughly equal to - \nSelect and explain. \nA. 250 ml, B. 350 ml, C. 500 ml, D. 600 ml', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]