Answer:
The correct answer would be C.) Fungus used for pest control.
In agriculture , fungi are used for humus production, biological pest control, and researches.
Fungi degrade the organic wastes (such as dead plants and animals) and produce humus which provide most of the nutrients required for the growth and development of a plant.
In biological pest control, fungi are used to control the population of many nematodes and insects. For example, Aschrsonia aleyroids, Cordyceps melonhae, Empausa sapulcrhalis, et cetera are used as insecticides in agriculture.