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: Pharmacology
[{'content': 'High concentration of bupivacaine during labour is contraindicated due to its \nSelect and explain. \nA. CNS depressant action, B. CNS stimulant action, C. Cardiotoxicity, D. Hypersensitivity reaction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]