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 their face value and sold at a premium on a later date.
B) Such bonds make regular interest payments.
C) Such bonds are purchased at a discount, below their face value.
D) Such bonds have a lower face value as compared to other bonds of similar term.