Ascomycetes are also known as sac fungi and include examples like Neurospora, which is used in genetic research, so (I) matches with . Deuteromycetes, often called fungi imperfecti due to their lack of a known sexual stage, include Colletotrichum, a genus responsible for plant diseases like anthracnose, so (II) matches with . Phycomycetes, which include simpler fungi such as water olds, are represented by Albugo, a parasitic fungus causing white rust in plants, hence (III) matches with . Finally, Basidiomycetes, known for producing basidiospores, include Ustilago, a smut fungus that infects cereals like maize, so (IV) matches with .