What happens right before rna polymerase begins to work?
a. the dna double helix unwinds.
b. rna polymerase reaches the end of the gene.
c. mrna detaches and moves to the ribosomes.
d. nucleic acids attach to the bases in the dna.

D. Nucleic acids attach to the bases in the DNA.

Explanation:

Transcription begins when an enzyme called RNA  polymerase  is added to the DNA template and begins a new chain a new chain to produce complementary RNA.

During the RNA synthesis transcription takes place, then the cap and tail is added and then splicing occurs.

RNA polymerase moves from the 3' end to the template strand creating the RNA-DNA double helix or similar the base sequences. This makes a chain with each sugar by the set of bonds called phosphodiaster linkage. Then, the enzyme unwind the DNA and begins the synthesis of RNA.

Therefore, D. Nucleic acids attach to the bases in the DNA.