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': 'Period of onset in tetanus refers to the time between: \nSelect and explain. \nA. First injury to spasm, B. First symptom to spasm, C. First spasm to death, D. Trismus to laryngeal spasm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]