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': 'Which system is primarily affected by tetanus? \nSelect and explain. \nA. Hematological, B. Nervous, C. Skeletal, D. All', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Nervous REF: Harrison\'s Internal Medicine 17th edition chapter 133 "Tetanus is a neurologic disorder, characterized by increased muscle tone and spasms that is caused by tetanospasmin, a powerful protein toxin elaborated by Clostridium tetani"', 'role': 'assistant'}]