Answer:
A. They are synthesized. is the correct answer.
Step-by-step explanation:
protein synthesis is the method of producing proteins within the cell
In the endoplasmic reticulum on the surface of a rough endoplasmic reticulum, proteins are synthesized.
The rough endoplasmic reticulum is embraced with ribosomes on its external surface and it is involved in protein synthesis.
The protein enters the rough endoplasmic reticulum, by a pore and protein is folded in the rough endoplasmic reticulum, and after that, it is sent to the Golgi apparatus.