The cellular component of protein synthesis is :

Ribosomes >> Rough endoplasmic reticulum Rough ER is that ER on which ribosomes are attached and protein synthesis occurs in ribosomes. So, best answer here is 3. Fig.: Free ribosomes present in cytoplasm (not attached to ER) Fig.: Ribosomes attached to cytosolic side of ER BUT SER is responsible for the synthesis of lipids, in detoxification and Ca sequestration & release.