Capella has a 10% coupon rate bond with a $1,000 face value. Interest is paid semiannually, or every six months, with 20 years to maturity. Investors require a 12% yield. Which of the following would you use to calculate the value of Capella's bond?

a. 100[1-1/(1+.12)²⁰/.12] + 1000/(1+.12)²⁰

b. 100[1-1/(1+.06)²⁰/.12] + 1000/(1+.06)²⁰

c. 100[1-1/(1+.12)⁴⁰/.12] + 1000/(1+.06)⁴⁰

d. 100[1-1/(1+.06)⁴⁰/.12] + 1000/(1+.06)⁴⁰

e. None of the above