The function of RNA polymerase enzyme is to synthesise

Explanation

RNA polymerase does not synthesize DNA from an mRNA template; that process is called reverse transcription and is carried out by the enzyme reverse transcriptase, not RNA polymerase, option D is incorrect. It also does not make mRNA from tRNA molecules because tRNA is used in translation, not as a template for RNA synthesis, and no biological system uses tRNA to produce mRNA hence option C is also incorrect. RNA polymerase likewise cannot synthesize a polypeptide from an mRNA template; polypeptides are made during translation by ribosomes, not by RNA polymerase. The only correct function of RNA polymerase is to synthesize mRNA from a DNA template during transcription, where it reads the DNA sequence and builds a complementary RNA strand. Option A is the correct answer.