Which PCR Step Causes the Denaturation of Double-Stranded DNA?
A)add $\circ$

Which PCR step causes the denaturation of double-stranded DNA?

A) add DNA polymerase and nucleotides at 72 ^$\circ$ C
B) cool DNA to between 50 ^$\circ$ C and 65 ^$\circ$ C
C) add primers
D) heat target DNA to 94 ^$\circ$ C
E) repeat the cycle of heating and cooling