Question

The function of rRNA is to

Answer 1

rRNA is the site where proteins are synthesized (made).

Answer 2

The r in rRNA stands for "ribosomal" and, as the answer above indicates, the ribosomes are the site where proteins are made by the joining together of amino acids according to the instructions received via messenger (m) RNA.

More information (much of it is too technical for me but maybe you will understand it):
http://en.wikipedia.org/wiki/Ribosome
http://en.wikipedia.org/wiki/Translation%20%28biology%29
http://en.wikipedia.org/wiki/tRNA
and of course http://en.wikipedia.org/wiki/rRNA

Answer 3

the function of ribosomal RNA is to form ribosome which are the sites for protien syntesis