21. You are managing a portfolio of $10 million with two bonds: a zero-coupon bond with maturity of 10 years, and a perpetuity, each currently yielding 4%, what should be the weight of the zero-coupon bond in your portfolio if your target duration is 16 years? a. 31.25% b. 50% 62.5% d. 68.75% e. None of the above options is correct