Which of the followingdebt securitiesis trading at a premium?

a. a 15-year bond with a $10,000 face value whose yield to maturity is 8.0% and coupon rate is 7.8% APR paid semiannually

b. a five-year bond with a $2000 face value whose yield to maturity is 7.0% and coupon rate is 7.2% APR paid semiannually

c. a ten-year bond with a $4000 face value whose yield to maturity is 6.0% and coupon rate is 5.9% APR paid semiannually

d.a two-year bond with a $50,000 face value whose yield to maturity is 5.2% and coupon rate is 5.2% APR paid monthly