Biology

The correct answer is: B.Endoplasmic reticulum (ER).

The endoplasmic reticulum (ER) is the internal membrane system found in eukaryotic cells. It plays a crucial role in the synthesis of various macromolecules, including lipid components of the cell membrane. The ER is divided into two types:

1.Smooth endoplasmic reticulum (SER): Involved in lipid synthesis, detoxification, and metabolism of carbohydrates.

2.Rough endoplasmic reticulum (RER): Studded with ribosomes and involved in protein synthesis and modification.