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': 'Epinephrine added to a solution of lignocaine for a peripheral nerve block will : \nSelect and explain. \nA. Increase risk of convulsions, B. Increase the duration of action of the local anesthetic, C. Both (a) and (b), D. None of these', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]