Are chemicals that are essential to all cellular activity, the body convert carbohydrates and fats into energy.

The answer is vitamins

Explanation:

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

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