Which of the Following Characteristics Apply to Exchange-Traded Funds (ETFs)

Which of the following characteristics apply to exchange-traded funds (ETFs) ?
I. Unlimited number of outstanding shares.
II. Typically track the performance of some index.
III. Market prices reflect demand for the fund rather than NAV.
IV. Shares are purchased from and redeemed by the investment company managing the fund.

A) I and II only
B) II and III only
C) I, II and III only
D) I, II and IV only