What is the function of the Rough Endoplasmic Reticulum?

The Rough Endoplasmic Reticulum (RER) is primarily known for its role in protein synthesis, making the correct answer B. The RER is studded with ribosomes on its cytoplasmic surface, which gives it a "rough" appearance. These ribosomes are the sites of translation, where messenger RNA (mRNA) is translated into polypeptide chains or proteins.

Once proteins are synthesized in the Rough Endoplasmic Reticulum, they are often folded and modified before being transported to their next destination, which could involve secretion from the cell or incorporation into cellular membranes. This highlights the RER's crucial role in the synthesis and initial processing of proteins that are essential for various cellular functions, including enzyme production, hormone secretion, and structural components.

While options related to energy production, transport and storage, and cell division describe important cellular processes, they do not reflect the primary function of the Rough Endoplasmic Reticulum. The focus on protein synthesis emphasizes its importance in maintaining cellular health and function.