What are primers?

A. Primers are the short sequences at the end of the nucleotide sequences which are used for amplification

B. Primers are the short sequences which are complementary to the nucleotides at the end of the sequence which is to be amplified

C. Primers are the short sequences present anywhere in the nucleotide sequence to be amplified

D. Primers are the short sequences which are complementary to the nucleotides anywhere in the sequence to be amplified

Explanation: Primers are short nucleotide sequences which are complementary to the stretches at the ends of the DNA sequence to be amplified.