Final answer:
The correct answer is A.Cryptococcus neoformans is characterized by encapsulated budding yeast cells. It is not a filamentous pseudohyphae, a Gram-negative bacilli, or a spirochete.
Step-by-step explanation:
The physical features of Cryptococcus neoformans include budding yeast cells and a large capsule, particularly evident in a negative stain micrograph.
Cryptococcus neoformans is not filamentous pseudohyphae like some fungi such as Candida albicans, nor is it a Gram-negative bacilli or spirochetes as it is a yeast.
The presence of a capsule is a major virulence factor for this fungal pathogen, which is not typical of bacteria or other types of fungi.
In an India ink-negative stain, the encapsulated yeast cells of Cryptococcus neoformans can be observed, showing thick capsules around the spherical cells.
This characteristic is important for identifying the pathogen and understanding its role in infections.
The capsule contributes to the organism's ability to evade the host's immune system, making it a significant virulence factor.