**Core Concept**
Intravenous amphotericin B is an antifungal medication used to treat serious fungal infections, particularly those caused by susceptible organisms. It works by binding to ergosterol in the fungal cell membrane, disrupting its integrity and leading to cell lysis.

**Why the Correct Answer is Right**
The empirical use of intravenous amphotericin B is indicated in cases of severe, suspected, or proven fungal infections when the causative organism is not yet identified. This approach is often used in critically ill patients or those with neutropenia, where the risk of fungal infection is high. Amphotericin B is effective against a broad spectrum of fungal pathogens, including Candida, Aspergillus, and Histoplasma species.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because amphotericin B is not typically used as a first-line treatment for superficial fungal infections, such as ringworm or athlete's foot. Oral antifungal agents are preferred for these conditions.

**Option B:** This option is incorrect because while amphotericin B can be used to treat fungal meningitis, it is not the first choice for this condition. Other antifungal agents, such as flucytosine, may be used in combination with amphotericin B.

**Option C:** This option is incorrect because amphotericin B is not used to treat viral infections. It is specific to fungal pathogens and has no activity against viruses.

**Clinical Pearl / High-Yield Fact**
When using intravenous amphotericin B, it's essential to monitor renal function closely, as the medication can cause nephrotoxicity. This is particularly important in patients with pre-existing kidney disease or those receiving other nephrotoxic agents.

**Correct Answer: C. Severe, suspected, or proven fungal infections when the causative organism is not yet identified.**