Answer;
Rough endoplasmic reticulum
Explanation;
Rough endoplasmic reticulum is among the organelles that are found in eukaryotic cells. The reason as to why it is called rough is because it has ribosomes attached to its surface.
Its main function is to produce proteins. It is made up of cisternae, tubules and vesicles. The cisternae consists of flattened membrane disks, which are involved in the modification of proteins.
Once enough proteins have been synthesized, they are transferred from the Rough endoplasmic reticulum to the Golgi apparatus via membrane-bound vesicles.