Clamworms and earthworms both belong to phylum Annelida. Curiously, earthworms have a thin cuticle outside of their epidermis and clamworms do not. Considering the relationship between an organism's form/function and its environment, which of the following provides the MOST logical explanation for this difference?

a. The cuticle maintains salt balance in a marine environment.
b. The cuticle provides protection against predators.
c. The cuticle prevents water loss in a terrestrial environment.
d. The cuticle allows for improved gas exchange.

c. The cuticle prevents water loss in a terrestrial environment.

Explanation:

The earthworms have a thin cuticle outside their epidermis. The cuticle performs different functions in the worm body. The cuticle protects the worm from predators. The thin cuticle remains moist with the slimy mucus. The cuticle helps in the exchange of gases from the external environment. The cuticle helps in absorbing the oxygen from the external environment whereas it expels the carbon dioxide to the external environment. The cuticle prevents the loss of moisture and allows the gaseous exchange which facilitates the survival of the worm in a harsh terrestrial environment.

i think the answer would be d