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: Medicine
Metronidazole is indicated in the treatment of which one of the following ? 
Select and explain. 
A. Traveller's diarrhea, B. Escherichia coli-induced diarrhoea, C. Cryptosporidium-induced diarrhea, D. Helicobacter pylori infection
D: Helicobacter pylori infection
Answer: D: Helicobacter pylori infection 
Explanation: None