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

Answer: A. Certain species of ANTS are well-known cultivators of fungi. The classic example is the LEAFCUTTER ANTS of the tribe ATTINI (genus ATTA and ACROMYRMEX) found in the Americas. They are among the few non-human animals that practice 'agriculture'. Their fungus-cultivation behaviour: - Worker ants cut and carry leaf fragments to underground nests. - Leaf pieces are chewed and mixed with saliva to create a substrate. - The substrate feeds a specialised cultivar fungus (genus Leucoagaricus / Lepiota family). - The ants harvest specialised swollen hyphae ('gongylidia') from the fungus as food. - The relationship is obligate mutualism — neither partner survives independently in the wild. - The ant colony also actively weeds out competing fungi and parasites (such as Escovopsis) and culture beneficial bacteria (Pseudonocardia) on their bodies as antibiotics. This is one of the most cited examples of complex insect agriculture in textbooks; the evolution of fungus-farming in attine ants is dated to ~50-60 million years ago. Distractors: (B) Cockroaches consume detritus but do not cultivate fungi. (C) Crabs scavenge or filter feed; no fungal cultivation. (D) Spiders are predators; no fungal cultivation. (Note: termites of subfamily Macrotermitinae also cultivate fungi but are not in the options.) Source: NCERT Class 12 Biology — Ecology / E. O. Wilson, 'The Ants'.