Q.
Agaricus, Alternaria and Aspergillus are genera of fungi which are included in three different classes. The respective order of these classes will be:
Agaricus is commonly called mushroom and all mushrooms are included in class basidiomycetes because their spores are called basidium/basidia. Alternaria is member of class deuteromycetes which include imperfect fungi because their only asexual stage is known. Aspergillus is member of class Ascomycetes, they have spores called ascus/asci.