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: Gynaecology & Obstetrics
[{'content': 'Treatment of choice in Gardenella vaginitis in pregnancy : \nSelect and explain. \nA. Clindamycin, B. Metronidazole, C. Ehromycin, D. Tetracycline', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Metronidazole', 'role': 'assistant'}]