Answer:
D. Use the polymerase chain reaction
Explanation:
Polymerase chain reaction (PCR) is a molecular technique used to make multiple copies or amplify a particular DNA sample. This enables scientist conduct thorough genetic analysis on minute sample of DNA, simply by amplifying it to a large quantity.
The PCR machine is usually used to amplify DNA fragment. The DNA fragments undergo three major steps successively: denaturation, annealing and elongation