The correct option is C All of the above
Endoplasmic reticulum (ER) is a membrane-bound organelle found in all eukaryotic cells except mature erythrocytes. ER is of two type smooth endoplasmic reticulum and rough endoplasmic reticulum. Smooth endoplasmic reticulum is found at the periphery of the cell i.e., towards the plasma membrane and they are devoid of ribosomes. Rough endoplasmic reticulum has rough surface due to the presence of ribosome and they are present towards the nucleus and attached with the karyotheca and the membrane of Golgi apparatus. Thus, the correct answer is option D.