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': "The mucogingival junction can be demonstrated by \nSelect and explain. \nA. Gention boiler, B. Schiler's potassium solution., C. Disclosing solution., D. Chlorhexidine.", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lugols iodine (or) schillers solution is used to stain keratinized gingival.', 'role': 'assistant'}]