An enzyme is a biomolecule that increases the rate of a chemical reaction. an enzyme is a kind of

catalyst

Explanation:

Enzymes are proteinous molecules that functions as to speed up the rate of reactions in living organisms.

Catalysts are substances that speeds up the rate of chemical reactions.

Both enzymes and catalysts are not used up during reactions.

Hence, an enzymes are considered to be a kind of catalyst in biological systems.

i think that d. wind is the answer.   i missed the question when i answered a. currents.