Which Is NOT True of Protein Translation

Which is NOT true of protein translation?

A) About 10% of cell proteins are completely synthesized and reside in the cytosol.
B) A single mRNA in the cytosol may have multiple ribosomes translating it at the same time.
C) Ribosomes that reside permanently on the rough ER translate only proteins destined for secretion from the cell.
D) Nascent proteins with a signal peptide at their amino terminus bind a signal recognition particle that binds an ER receptor.
E) Polysomes are multiple ribosomes translating the same mRNA.