Which of the following statements is most correct?

a. All else equal, if a bonds yield to maturity increases, its price will fall.

b. All else equal, if a bond is down graded by the rating agencies its yield to maturity will increase.

c. If a firm has two bond issues that are identical except one is subordinate to the other, the subordinate issue will have a higher yield to maturity than the other issue.

d. A B and C are correct.

e. None of the above are correct