Answer: C:It helps transcribe the DNA strand.
Explanation:
RNA polymerases are enzymes that catalyze RNA synthesis using a DNA strand as a template. This process is called transcription. Unlike DNA polymerases, RNA polymerases can start a new RNA strand from a DNA template without the need of a primer. Prokaryotes have only one type of RNA polymerase, while eukaryotes have three. RNA polymerases are generally complex molecules formed by multiple polypeptide chains and have a mass of about 500,000 Dalton.
Although the transcriptional mechanism in eukaryotes is the same as in prokaryotes, the RNA synthesis machinery in nucleated cells is considerably more complex than in bacteria. In eukaryotes, there are three types of RNA polymerase, each responsible for the transcription of a specific set of genes. These enzymes are structurally similar to each other and are called RNA polymerases I, II and III. All of them are more complex than prokaryotic RNA polymerase, being formed by at least 12 subunits, some of which are common to all subunits.
