All of the Following Statements Concerning the Endoplasmic Reticulum (ER)

All of the following statements concerning the endoplasmic reticulum (ER) are correct EXCEPT:

A) Rough ER contains ribosomes.
B) The ER functions primarily as a transport system within the cytoplasm of eukaryotic cells.
C) The ER is a system of hollow tubules.
D) The ER is continuous with the outer membrane of the nuclear envelope.
E) Rough ER is involved in the synthesis of proteins and lipids.