C. It allows scientists to quickly make many copies of DNA.
Explanation:
Polymerase chain reaction (PCR) is a technique using which several copies of a DNA template can be made.
For DNA fingerprinting the DNA is usually obtained from samples such as hair, saliva, blood, etc.
The amount of DNA in samples such as hair or saliva is not enough and thus, amplification of the amount using PCR allows a much reliable DNA fingerprinting to take place.
