Please explain your answer, thank you :)

3. A firm has an issue of $1,000 par value bonds with a 9 percent stated interest rate outstanding. The issue pays interest annually and has 20 years remaining to its maturity date. If bonds of similar risk are currently earning 9 percent, the firm's bond will sell for today. A) $1,000 B) $716.67 C) $840.73 D) $1,123.33