A company is planning to raise $$1,000,000$ to finance a new plant. Which of the following statements is CORRECT?

a$.$ If debt is used to raise the million dollars, but $$500,000$ is raised as first mortgage bonds on the new plant and $$500,000$ as debentures, the interest rate on the first mortgage bonds would be lower than it would be if the entire $$1$ million were raised by selling first mortgage bonds.

b$.$ If debt is used to raise the million dollars, the cost of the debt would be higher if the debt were in the form of a mortgage bond rather than an unsecured term loan.

c$.$ The company would be especially eager to have a call provision included in the indenture if its management thinks that interest rates are almost certain to rise in the foreseeable future.

d$.$ If debt is used to raise the million dollars, the cost of the debt would be lower if the debt were in the form of a fixed$-$rate bond rather than a floating$-$rate bond.

e$.$ If two classes of debt are used $($with one senior and the other subordinated to all other debt$),$ the subordinated debt will carry a lower interest rate.