Answer:C. smooth ER
Explanation:the endoplasmic reticulum is a membrane bound organelle found in the cytoplasm of the cell.it has a highly folded appearance.
Its function in the cell is the transportation of cellular products.
There are two types of endoplasmic reticulum;the rough endoplasmic reticulum and the smooth endoplasmic reticulum.
The rough endoplasmic reticulum have ribosomes attached to them ,giving them a granular appearance.the ribosomes synthesis proteins,which the rough endoplasmic reticulum transports outside or within the cell.
The smooth endoplasmic reticulum do not have ribosomes attached to it.its functions is to synthesis lipids.
It is also involved in the production of steroid hormones in the adrenal cortex and endocrine glands