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: Dental
Metronidazole is NOT effective in the treatment of 
Select and explain. 
A. Amoebiasis, B. Infections due to Bacteroides fragilis, C. Infections due to Pneumocystis carinii, D. Acute necrotizing ulcerative gingivitis
C: Infections due to Pneumocystis carinii
Answer: C: Infections due to Pneumocystis carinii 
Explanation: None