Which bonds is the most expensive? A. coupon rate 9%, yield to maturity of 4%, term to maturity of 10 years, face value 1000 B. coupon rate 9%, yield to maturity of 12%, term to maturity of 10 years, face value 1000. C. coupon rate 5%, yield to maturity of 6%, term to maturity of 10 years, face value 1000. D. coupon rate 5%, yield to maturity of 10%, term to maturity of 10 years, face value 1000