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: Pharmacology
[{'content': 'Which of the following is a characteristic of tetracycline stains? \nSelect and explain. \nA. There is less deposition in dentine as compared to enamel, B. Is always accompanied by hypoplastic defects, C. Stains are dark brown in color, D. Stained teeth fluoresce light yellow under U.V. light', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]