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: Medicine
[{'content': 'Pasteurized milk is most commonly tested by \nSelect and explain. \nA. Phosphatase test, B. Standard plate count, C. Coliform Count, D. Holder method', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Phosphatase test - widely used test.', 'role': 'assistant'}]