Answer:
In transcription, RNA polymerase links nucleotides to form mRNA.
Step-by-step explanation:
The process of transcription implies the formation of a mRNA. Is the first step to genetic expression, and it involves the making of a "copy" of the DNA in RNA. This process is performed by the enzyme RNA polymerase, that links the nucleotides to form the mRNA strand.
The incise b is false, the promoter region acts as a binding site to the RNA polimerase, not the mRNA.
The incise c is false, althoug there are genes in both DNA strands, they do not act simultaneously as templates.
The incise d is false, since the polypeptide formation is the TRANSLATION step, after transcription, according to the Central dogma of molecular biology.