The correct answer is: Free ribosomes are located in the cytoplasm, whereas attached ribosomes are embedded on the endoplasmic reticulum.
Free ribosomes produce proteins which are released into the cytosol and used within the cell. On the other hand, attached (membrane-bound) ribosomes synthesize proteins that are needed within the plasma membrane or are released from the cell. The newly synthesized polypeptide chains are inserted directly into the endoplasmic reticulum by the attached ribosome and are then transported to their destinations where they will be secreted.
