Cnidarian, also called coelenterate are mostly marine animals. They include the corals, hydras, jellyfish, Portuguese menof-war, sea anemones, sea pens, sea whips, and sea fans.

The relationship between cnidarians and dinoflagellate algae is termed as “symbiotic”, because both the animal host and the algae are benefiting from the association.

It is a mutualistic interaction Fungi have several mutualistic relationships with other organisms. In mutualism, both organisms benefit from the relationship. Two common mutualistic relationships involving fungi are mycorrhiza and lichen.

Termites have a mutualistic relationship with protozoa that live in the insect’s gut. The termite benefits from the ability of bacterial symbionts within the protozoa to digest cellulose. Hence option (d) is the correct answer

Source: CSP2021