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': 'Disclosing agents are used to motivate and educate patients about plaque and oral hygiene methods. These agents can make the patient visualise subgingival plaque. \nSelect and explain. \nA. Both are true, B. Both are false, C. 1st is true, 2nd is false, D. 2nd is true, 1st is false', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]