Answer:
D. 20 year maturity.
Step-by-step explanation:
The bond has stated interest rate of 7% and the yield is 7.50% . The bond is sold at discount to its par value. The bond is issued for 20 years maturity and since it is at discount then the bonds will be held till maturity to improve yield on bonds. The price of the bond will be calculated based on 20 years maturity.