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: Microbiology
[{'content': 'Optimal percentage of NaCI for V cholerae ? \nSelect and explain. \nA. 1%, B. 2%, C. 3%, D. 4%', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., 1%", 'role': 'assistant'}]