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: Social & Preventive Medicine
[{'content': 'Methylene blue reduction test is done for estimating – \nSelect and explain. \nA. Fat content of milk, B. Sugar content of milk, C. Protein content of milk, D. Bacterial activity in milk', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]