**Core Concept**
The question is testing the student's knowledge of antifungal agents, specifically those that belong to the class of anti-metabolites. Anti-metabolites are a group of drugs that inhibit the growth of microorganisms by interfering with their metabolic processes.

**Why the Correct Answer is Right**
Flucytosine (5-fluorocytosine) is an antifungal agent that acts as an anti-metabolite. It is converted to 5-fluorouracil (5-FU) within fungal cells, which then interferes with DNA synthesis by inhibiting thymidylate synthase. This leads to the disruption of fungal DNA replication and ultimately results in fungal cell death.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided, so we'll move on to the next one.
* **Option B:** This option is not relevant to antifungal agents or anti-metabolites.
* **Option D:** This option is not a known antifungal agent or anti-metabolite.

**Clinical Pearl / High-Yield Fact**
Flucytosine is often used in combination with amphotericin B for the treatment of cryptococcal meningitis, a serious fungal infection of the central nervous system.

**Correct Answer: C. Flucytosine**