Answer:
Here is the complete question
The initiation of transcription requires melting of the DNA double helix, i.e. separating hydrogen-bonded base pairs, immediately upstream of the +1 site. In E. coli this melting is accomplished by ___________.
-DNA helicase unwinding the double helix around the +1 site.
-DnaA:ATP complexes binding to and twisting the double helix at the +1 site.
-RNA polymerase obtaining the energy to cause separation of strands from ATP hydrolysis.
-binding of the DNA complexes to the double helix at the +1 site and twisting of the double helix.
-bases at the promoter region flipping outward from the double helix into pockets on the polymerase.
And the answer is.....
bases at the promoter region flipping outward from the double helix into pockets on the polymerase.