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': 'Drug of choice for bacterial vaginosis: March 2011 \nSelect and explain. \nA. Ciprofloxacin, B. Doxycycline, C. Teracycline, D. Metronidazole', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D: Metronidazole The 7-day course of metronidazole 500 mg twice daily is effective in 85% of courses of bacterial/ gardnerella vaginosis, whereas a single dose of 2 gm cures only 45%.', 'role': 'assistant'}]