Which of the following statements is correct about bound ribosomes?
a. They are attached to the rough E.R. and make proteins destined for use within the cell.
b. They are attached to the rough E.R. and make proteins destined for secretion outside of the cell or for use within lysosomes.
c. They are found alone in the cytoplasm and make proteins destined for use within the cell.
d. They are found alone in the cytoplasm and make proteins destined for secretion outside of the cell.