An animal that respires but has no respiratory organs is the:

Correct answer: (c) Earthworm

Explanation

The earthworm has no lungs, gills or tracheae. It breathes through its moist skin (cutaneous respiration): oxygen dissolves in the moisture on the skin and diffuses into the blood vessels just below it. That is why earthworms must live in damp soil.

The others have respiratory organs: fish breathe through gills, frogs through lungs (and also their skin), and cockroaches through tracheae that open at spiracles.