**Core Concept**
Cryptococcus neoformans is a type of encapsulated yeast that primarily affects immunocompromised individuals. It is a pathogenic fungus that causes cryptococcosis, particularly cryptococcal meningitis in HIV/AIDS patients. The polysaccharide capsule surrounding the yeast cell plays a crucial role in its virulence and resistance to phagocytosis.

**Why the Correct Answer is Right**
The correct option is Cryptococcus neoformans, which is an encapsulated yeast. The polysaccharide capsule of C. neoformans is composed of glucuronoxylomannan, which helps the yeast evade host immune responses and survive within the host. The capsule is also responsible for the organism's ability to resist phagocytosis and establish infection, particularly in immunocompromised individuals such as those with HIV/AIDS.

**Why Each Wrong Option is Incorrect**
**Option A:** Histoplasma capsulatum is a dimorphic fungus that can cause histoplasmosis, but it is not encapsulated. It is an intracellular pathogen that primarily affects the lungs.
**Option B:** Coccidioides immitis is a dimorphic fungus that causes coccidioidomycosis, but it is not encapsulated. It is a soil-dwelling fungus that can cause respiratory disease and disseminated infection in immunocompromised individuals.
**Option C:** Paracoccidioides brasiliensis is a dimorphic fungus that causes paracoccidioidomycosis, but it is not encapsulated. It is a soil-dwelling fungus that can cause respiratory disease and disseminated infection in immunocompromised individuals.

**Clinical Pearl / High-Yield Fact**
Cryptococcal meningitis is a common opportunistic infection in HIV/AIDS patients, particularly those with CD4 counts below 100 cells/μL. The diagnosis of cryptococcal meningitis involves cerebrospinal fluid (CSF) analysis, which typically shows elevated protein levels, decreased glucose levels, and a high white blood cell count with a predominance of lymphocytes.

**Correct Answer:** C.