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: Microbiology
[{'content': 'Main site of action of tetanus toxin: \nSelect and explain. \nA. Presynaptic terminal of spinal cord, B. Postsynaptic terminal of spinal cord, C. Neuromuscular junction, D. Muscle fibers', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is. a' i. e. Presynaptic terminal of spinal cord", 'role': 'assistant'}]