This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Surgery
[{'content': 'according NHS protocol time frame of surgery is ? \nSelect and explain. \nA. sign out -sign in -time out, B. sign out-time out-sign in, C. sign in - time out- sign out, D. sign in -sign out-time out', 'role': 'user'}, {'content': 'Answer: C \nExplanation: ref : who.gov / schwaz text book general surgery', 'role': 'assistant'}]