The price of a bond with an 7.2% coupon rate paid semi-annually, a par value of $1,000, and fifteen years to maturity is the present value of

A) 15 payments of $36 at 6-month intervals plus $1,000 received at the end of the fifteenth year.

B) 30 payments of $36 at 6-month intervals plus $1,000 received at the end of the fifteenth year.

C) 15 payments of $72 at 6-month intervals plus $1,000 received at the end of the fifteenth year.

D) 30 payments of $72 at one-year intervals plus $1,000 received at the end of the 30th year.

Explain your answer.