**Core Concept**
Cryptococcus neoformans is a type of encapsulated yeast that causes cryptococcosis, primarily affecting immunocompromised individuals. It is an opportunistic pathogen that can lead to severe pulmonary and central nervous system infections.

**Why the Correct Answer is Right**
Cryptococcus neoformans is an encapsulated yeast, meaning it has a thick polysaccharide capsule that helps it evade the host's immune system. This capsule is composed of glucuronoxylomannan (GXM), a polysaccharide that inhibits phagocytosis and activates the host's inflammatory response. The yeast is typically found in soil contaminated with pigeon droppings and can be inhaled, leading to pulmonary infections in immunocompromised individuals.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Cryptococcus neoformans is actually a type of encapsulated yeast, not a non-encapsulated one. The capsule is a key virulence factor for this pathogen.
**Option B:** This option is incorrect because Cryptococcus neoformans is a type of fungus that can cause severe infections in immunocompromised individuals, particularly those with HIV/AIDS.
**Option C:** This option is incorrect because Cryptococcus neoformans is typically found in soil contaminated with pigeon droppings, not in human feces.

**Clinical Pearl / High-Yield Fact**
Cryptococcal meningitis is a life-threatening complication of cryptococcosis that requires prompt treatment with antifungal medications, such as amphotericin B and flucytosine.

**Correct Answer: D.**