This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-Parasitic Drugs, Subject name: Pharmacology
Metronidazole is LEAST likely to be effective in the treatment of: 
Select and explain. 
A. Hepatic amoebiasis, B. Infection caused by Bacteroides fragilis, C. Pseudomembranous colitis, D. Pneumocystosis
D: Pneumocystosis
Answer: D: Pneumocystosis 
Explanation: Metronidazole is not used in the treatment of Pneumocystosis Its DOC is trimethoprime sulfomethoxazole (Cotrimoxazole) METRONIDAZOLE G - GIARDIASIS U - PEPTIC ULCER P - PMC T - TRICHOMONIASIS A - ANAEROBIC BACTERIA AMEOBIASIS