What is common between an earthworm, a cockroach and a centipede?
The correct option is D Haemocoel
Centipede shows no sexual dimorphism and so do earthworms.
Centipedes and cockroaches undergo incomplete metamorphism.
Earthworms don't have a chitinous exoskeleton.
The only common thing between the cockroach, centipede, and earthworms is that they have hemocoel. Hemocoel is a cavity, between the organs of arthropods and molluscs, through which the blood circulates. The blood in the hemocoel is called hemolymph.
Therefore, the correct answer is option D.