Which of the statements about the interest rate risk of a bond (when all other conditions are the same)? a. The closer the maturity, the higher the risk of interest rates. b. The higher the surface interest rate, the higher the risk of interest rate. c. There is no risk of interest rate on bonds traded at par. d. The greater the semiannual interest payments paid twice a year, the higher the interest rate. e. The less interest paid each time, the lower the risk of interest rate.