This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy: General Principles, Subject name: Pharmacology
A female presented with frothy, greenish vaginal discharge with a musty smell. On examination 'strawberry vagina' was noted. A diagnosis of trichomonas vaginalis was made. Drug of choice is: 
Select and explain. 
A. Metronidazole, B. Tetracycline, C. Erythromycin, D. Fluconazole
A: Metronidazole
Answer: A: Metronidazole 
Explanation: Ans. (A) Metronidazole(Ref: CMDT 2017/e p1531)The diagnosis is trichomonas vaginitis. The drug of choice is metronidazole or tinidazole