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': "A 30 year old lady is to undergo surgery under intravenous regional anesthesia for her left 'trigger finger'. Which one of the following should not be used for patient ? \nSelect and explain. \nA. Lignocaine, B. Bupivacaine, C. Prilocaine, D. Lignocaine + ketorolac", 'role': 'user'}, {'content': "Answer: B \nExplanation: Bupivacaine is contraindicated for intravenous regional anesthesia (Bier's block).", 'role': 'assistant'}]