Step-by-step explanation:
The organelle that manufactures proteins bound for secretion out of the cell is the rough endoplasmic reticulum (RER).
The RER is studded with ribosomes, which are responsible for the synthesis of proteins. Proteins that are synthesized by ribosomes on the RER are typically destined for secretion out of the cell, as well as for insertion into the cell membrane or for use within other organelles. As the polypeptide chains are synthesized on the ribosomes, they are translocated into the lumen (inner space) of the RER, where they are folded and modified by a number of enzymes and other proteins that are located within the RER.
Once the proteins are properly folded and modified, they are packaged into transport vesicles and transported to the Golgi apparatus for further processing and distribution to their final destination within the cell or outside of the cell.
Therefore, the correct answer is (b) rough endoplasmic reticulum.