What Happens Simultaneously with the Removal of RNA Primer by the 5'->3

Multiple Choice

What happens simultaneously with the removal of RNA primer by the 5'->3' exonuclease activity of DNA polymerase I?

A) The DNA double helix is unwound.
B) The gap left by the removal of the RNA primer is filled in with deoxyribonucleotides.
C) The gap left by the removal of the RNA primer is filled in with ribonucleotides.
D) DNA is supercoiled extensively.