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': 'A patient died on dental chair due to overdose of LA, cause for this can be \nSelect and explain. \nA. Apnea, B. Hypercapnea, C. Cardiac arrest, D. Dyspnea', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]