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': 'Traces of which of the following antibiotics can be found in the gingival fluid after administration: \nSelect and explain. \nA. Tetracycline, B. Lincomycin, C. Clindamycin, D. Penicillin G', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]