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 the drug of choice for 
Select and explain. 
A. All periodontal disease, B. ANUG, C. Juvenile periodontitis, D. Herpes simplex
B: ANUG
Answer: B: ANUG 
Explanation: None