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: Anaesthesia
[{'content': 'Which of the following local anaesthetic should not be alkalinized with soda bicarbonate \nSelect and explain. \nA. Lignocaine, B. Procaine, C. Bupivacaine, D. Benzocaine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Local anaesthetic drug if dissociated –it wont act on sodium channel.\nSo drug is kept undissociated by adding soda bicarbonate to maintain pka 7.7→ 8.2\nBut for bupivacaine soda bicarbonate is not used as it gets precipitated.', 'role': 'assistant'}]