The role of rrna in gene expression is to?

The correct answer is rRNA plays an important role during translation (protein synthesis) of mRNA.

Explanation:

Ribosomal RNA or rRNA are the RNA molecules which build up the site for protein synthesis known as ribosomes.

Ribosome synthesis takes place in nucleolus where two types of rRNA molecules associates with proteins, one in large subunit and one in the small subunit to form ribosomes.

These ribosomes physically moves along an mRNA molecule and catalyze the assembly of amino acids where rRNA molecules performs the catalytic steps of protein synthesis that is stitches amino acids together and makes up proteins.

Thus,  rRNA plays an important role during translation (protein synthesis) of mRNA.