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: Dental
[{'content': 'Patient can be diagnosed for improper oral hygiene maintenance by \nSelect and explain. \nA. Proper dietary history, B. Disclosing agents, C. Lactobacillus count, D. Swab test', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]