The correct option is C Alternaria - Sexual reproduction absent - Deuteromycetes
Alternaria belongs to Deuteromycetes which lack sexual reproduction.
Phytophthora belongs to Phycomycetes. They are nonseptate coenocytic mycelium.
Mucor also belongs to Phycomycetes. They reproduce vegetatively via conjugation.
Agaricus belongs to basidiomycetes. They are saprophytic and not parasitic fungus.