Answer:
Option D , yeast
Step-by-step 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