Which of the following statements concerning medium-term notes and corporate bonds are true?

I. Medium-term notes differ from bonds in the manner in which they are distributed to investors when they are initially sold.
II. Typically, investment-grade corporate bond issues are underwritten by investment bankers.
III. Medium-term notes have traditionally been distributed on a best efforts basis by either an investment banking firm or dealers acting as agents.
IV. Medium-term notes are usually sold in relatively small amounts on either a continuous or an intermittent basis, while bonds are sold in large, discrete offerings.