Answer:
(C) biosynthesis of secretory proteins
Explanation:
The smooth endoplasmic reticulum has no ribosome attachment to its surface and are therefore not involved in the biosynthesis of secretory proteins.
The smooth ER is a network of membranes known as cisternae and functions in lipid and steroid hormone synthesis, detoxification of harmful metabolic products as well as the breakdown of glycogen granules to glucose.
The correct option is C.
