**Core Concept:** Cryptococcus neoformans is a pathogenic yeast that causes fungal infections in humans, particularly in immunocompromised individuals. The four options represent different properties of this organism.

**Why the Correct Answer is Right:** C. Cryptococcus neoformans is an encapsulated yeast that produces a polysaccharide capsule composed of glucuronoxylomannan (GXM) and glucuronoxylomannan-protein (GXM-protein). This capsule plays a crucial role in its virulence, protection from phagocytosis, and evasion from the host immune system.

**Why Each Wrong Option is Incorrect:**

A. Cryptococcus neoformans is not a Gram-positive organism. It is a fungus, and fungi are Gram-negative or -positive based on their cell wall composition.

B. Cryptococcus neoformans does not produce urease, an enzyme associated with the pathogenesis of some Gram-positive bacteria.

D. Cryptococcus neoformans is not exclusively an intracellular pathogen. Although it can invade host cells, it primarily causes infections in the extracellular environment, particularly in the lungs and central nervous system.

**Clinical Pearl / High-Yield Fact:** Cryptococcal meningitis caused by Cryptococcus neoformans is a significant fungal infection in immunocompromised patients, particularly those with HIV/AIDS. Early diagnosis and treatment are crucial to prevent complications and improve outcomes.

**Correct Answer:** D. Cryptococcus neoformans is not exclusively an intracellular pathogen. Although it can invade host cells, it primarily causes infections in the extracellular environment, particularly in the lungs and central nervous system.