Correct option (a) several ribosomes attached to a single mRNA
Explanation
The group of ribosomes together with the single mRNA molecules, they are translating is called polysome. They are formed by several ribosome attached to a single mRNA.
In eukaryotic cells the ribosomes are attached to rough endoplasmic reticulum by ribophorin protein. Electron microscopy reveals that membranes of homogenised endoplasmic reticulum disrupt to form closed vesicles called microsomes. Microsomes derived from rough endoplasmic reticulum are studied with ribosomes and are called rough ribosomes.
