**Core Concept**
Rhinosporidiosis is a chronic, granulomatous infection caused by Rhinosporidium seeberi, a protistan organism that primarily affects the mucous membranes of the nose, conjunctiva, and skin.

**Why the Correct Answer is Right**
Rhinosporidiosis is characterized by the formation of polyps containing spores of Rhinosporidium seeberi, which are ingested by macrophages and cause granulomatous inflammation. The infection is typically acquired through waterborne transmission, and the disease is more common in India and Sri Lanka. The polyps are composed of a loose connective tissue stroma with an abundance of multinucleated giant cells and eosinophils.

**Why Each Wrong Option is Incorrect**
**Option A:** Rhinosporidiosis is a bacterial infection.
This is incorrect because Rhinosporidium seeberi is a protistan organism, not a bacterium.

**Option B:** Rhinosporidiosis is a fungal infection.
This is incorrect because Rhinosporidium seeberi is a protistan organism, not a fungus.

**Option C:** Rhinosporidiosis is caused by Rhinosporidium seeberi through airborne transmission.
This is incorrect because Rhinosporidium seeberi is typically acquired through waterborne transmission.

**Clinical Pearl / High-Yield Fact**
Rhinosporidiosis is a rare but distinctive infection that can mimic other conditions such as angiofibroma or squamous cell carcinoma, and a definitive diagnosis can only be made by histopathological examination of the affected tissue.

**Correct Answer: B. Rhinosporidiosis is a fungal infection.**