Jeopardy! question: The answer is "because holders of zero$-$coupon bonds must pay taxes

each year on zero$-$coupon bonds as if they actually received the interest." The question is:

Why is the price of a zero$-$coupon bond less than its par $($face$)$ value?

Why is it illegal for individual investors to hold zero$-$coupon bonds?

Why are zero$-$coupon bonds bad investments for tax$-$deferred retirement plans such as IRAs?

Why is a typical investor more likely to hold zero$-$coupon bonds in a nontaxable account $($like a Roth

IRA$)$ than in a taxable account?