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 is false with regards to bupivacaine \nSelect and explain. \nA. Bupivacaine concentration for epidural anaesthesia is 0.5%, B. Bupivacaine concentration for spinal anaesthesia is 0.5%, C. Bupivacaine is used frequently for i.v regional anaesthesia, D. Bupivacaine is most potent local anaesthetic', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Bupivacaine is contraindicated in Bier’s block or IVRA.', 'role': 'assistant'}]