Which is a single-celled fungus? a. mold b. mushroom c. alga d. yeast

Option D , yeast

Explanation:

Most of the fungi are multi-cellular. Only yeast is a single celled fungi that usually arises on the old bread.

All other fungi's i.e mold, mushroom and alga are multi-cellular. Fungi's have a large multi cellular network of hyphae. These Hyphae filaments are made up of  tubular cells.

However, yeast being single celled fungi do not have hyphae.  

Hence, option D is correct

make   gliitsh plesea   !

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .