What happens immediately after RNA polymerase recognized and attaches to the promoter site on DNA?

A. RNA polymerase catalyzes the opening and begins unwinding the DNA strands.

B. RNA polymerase brings nucleotides to pair by RNA complementary base pairing.

C. RNA polymerase disconnects the RNA so that it can leave the DNA and move to the site of protein synthesis.

D. RNA polymerase forms peptide bonds to string amino acids together into proteins.