How Are Investors in Zero-Coupon Bonds Compensated for Making Such

How are investors in zero-coupon bonds compensated for making such an investment?

A) Such bonds are purchased at a discount to their face value.
B) Such bonds are purchased at their face value and sold at a premium at a later date.
C) The bond makes regular interest payments.
D) The face value of these bonds is less than the value of the bond when the bond matures.