Which yeast produces only blastoconidia on cornmeal Tween 80 agar?

The correct choice is based on the characteristic reproduction of Cryptococcus spp. on cornmeal Tween 80 agar. This species is known for producing only blastoconidia, which are a type of asexual reproductive structure that bud from the parent cell. These structures are well-documented in the life cycle of Cryptococcus and are particularly identifiable on specific media like cornmeal agar, which supports yeast growth and the observation of these budding forms.

In contrast, other options such as Candida spp. can produce a variety of reproductive forms, including pseudohyphae and blastoconidia, making them less specific for the question. Trichosporon spp. tends to produce both arthroconidia and blastoconidia, while Geotrichum spp. is noted for producing hyphae that fragment into arthroconidia rather than solely producing blastoconidia. As such, the uniqueness of Cryptococcus spp. in producing only blastoconidia is what solidifies it as the correct answer in this context.