Which of the following best describes the role of RNA polymerase in a cell? O A. It initiates translation of mRNA at the start codon for protein synthesis. O B. It reads the DNA molecule for synthesis of a complementary strand of MRNA. O C. It modifies an mRNA transcript by adding a poly-A tail and removing introns. D. It attaches to a DNA strand and unzips the molecule into two separate strands.

Pharmacology is a discipline of medicine that studies how medications interact with the systems and processes of living organisms, focusing on drug action mechanisms as well as therapeutic and other purposes.