Assertion : PCR primers must not have self complementary regions.
Reason : Self complementary regions result in hairpin structures adversely affecting the PCR.

Answer

A

Explanation

Primers are nucleotide sequences that serve as base for formation of new DNA strand. In PCR, primers are added on the ends of DNA strand to be copied and the primers are extended towards each other so that the DNA segment lying between the two primers is copied. If self complementary bases are present in primers than hydrogen bonds are formed between them and hairpin-like structure is formed. It makes the primers unsuitable for extension of strands in PCR.