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: Surgery
[{'content': 'Action of lignocaine is affected by all except \nSelect and explain. \nA. PH at the site of injection, B. Blood flow at the site of injection, C. Vasoconstrictor in the L.A solution, D. Action of cholinesterase at the site of injection', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]