The correct option is C participants as cofactor in enzyme catalysed reaction
An enzyme consists of a protein part (apoenzyme) and non-protein part (cofactor). The apoenzyme and cofactor together are called holoenzymes.
There are three kinds of cofactors - prosthetic groups, coenzymes and metal ions.
The organic cofactor includes the prosthetic groups and coenzymes while metal ions are the inorganic part.
NAD and NADP are types of coenzymes which contain the vitamin niacin. They participate as coenzymes in enzyme catalysed reactions.