Vitamins function as .........

The chemical nature of most prosthetic groups is ......... .

The similarity between $NAD^{+}$ and $NADP^{+}$ is that

Small molecules compared to the protein part of enzymes are known as:

What is an enzyme called when it is bound to an organic substance that is essential for its activity?

Consider the following statements:
$(A)$ Coenzyme or metal ion that is tightly bound to enzyme protein is called prosthetic group.
$(B)$ $A$ complete catalytic active enzyme with its bound prosthetic group is called apoenzyme.
Select the correct option.