The correct option is B Coenzymes
An enzyme consists of a protein part (apoenzyme) and non-protein part (cofactor). The apoenzyme and cofactor together form the holoenzyme.
There are three kinds of cofactors - prosthetic groups, coenzymes and metal ions. The organic co-factor includes the prosthetic group and coenzymes while metal ions are inorganic cofactors.
The coenzymes are transient organic groups which are not attached to the apoenzyme permanently like the prosthetic group.
The non-protein but organic part which is permanently attached to the enzyme is called prosthetic group.