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: Pharmacology
Which antifungal drug is an anti-metabolite? 
Select and explain. 
A. Ketoconazole, B. Flucytosine, C. Terbinafine, D. Griseofulvin
B: Flucytosine
Answer: B: Flucytosine 
Explanation: Flucytosine