Solution

Ribosomes are cell organelles that are formed of two subunits. Cytosolic eukaryotic ribosomes $$(80S)$$ are made up of $$60S$$ and $$40S$$ subunits, while prokaryotic ribosomes $$(70S)$$ are made up of $$50S$$ and $$30S$$ subunits.
They are also capable of forming polyribosomes during which many ribosomes are attached to $$mRNA$$. The purpose of ribosomes moving on mRNA is to synthesise proteins i.e., translation. Indeed, ribosomes have a very direct role in protein synthesis.
So, the correct answer is 'Have no role in protein synthesis'.