Certain species of which one of the following organisms are well known as cultivators of fungi?

Answer: (a) Ant

Leaf-cutter ants carry leaves into their nests to grow a fungus garden, which feeds the colony. (Some termites do this too.)

The idea

Leaf-cutter ants do not eat the leaves they carry. They chew them into a paste and grow a fungus on it, and the colony eats the fungus. The ants weed the garden, feed it and carry a piece of it to start each new nest. It is farming, invented by insects millions of years before humans.

Workers cut pieces of leaf → Carry them to the underground nest → Chew them into compost → Fungus grows on the compost → Ants eat the fungus

Also know

The ant cannot live without the fungus and the fungus is not found outside ant nests: a case of mutualism. In India, mound-building termites grow a fungus in the same way, and the mushrooms that sprout from old termite mounds are collected and eaten.