Final answer:
RNA polymerase is primarily responsible for c) transcription, which is the synthesis of RNA from a DNA template. Specifically, the sigma subunit of RNA polymerase is involved in the initiation phase of bacterial transcription. In eukaryotic cells, RNA polymerase II is tasked with transcribing most genes into pre-mRNA, which is then processed to mature mRNA.
Step-by-step explanation:
RNA polymerase is primarily responsible for transcription, which is the process of copying a segment of DNA into RNA (mRNA). This occurs during gene expression where the information stored in DNA is converted to a format used to build proteins. Thus, the correct answer to the original question is C) transcription.
During bacterial transcription, the sigma unit (σ subunit) of RNA polymerase is involved in the initiation phase. This unit helps RNA polymerase locate the start site of a gene and begin synthesis of the RNA strand. After initiation, the RNA polymerase continues to elongate the RNA transcript, and upon completion, terminates the transcription process.
It should be noted that RNA polymerase II, located in the nucleus of eukaryotic cells, synthesizes all protein-coding nuclear pre-mRNAs. Before mRNAs are translated into proteins, they undergo several processing steps. These steps transform the pre-mRNA into a mature mRNA form, ready for translation, which is the synthesis of proteins. So, RNA polymerase is not involved in translation, polyadenylation, DNA replication, or transformation.