Its "C"Oxygen because it is used as oxidative phosphorylation
I think the enzyme photolyase is activated by light and can repair thymine dimers caused by UV radiation. Exposure to UV radiation is the main factor that causes skin cells to become cancer cells. These enzymes are involved in the repair of ultraviolet light-induced DNA damage when activated by light absorption.
The body wall<span> of a star fish is made up of a thin cuticle, an epidermis with a single layer of cells, a thick dermis composed of connective tissue and a thin coelomic myoepithelial layer, which allows the longitudinal and circular musculature.</span>
Centrioles is the organelle.