Beginning with a zero$-$leverage company, as debt is substituted for equity in the capital structure $\_\_\_\_\_\_\_\_.$

Question $12$Select one:

a$.$

the overall cost of capital first declines, reaches a minimum, and then rises

b$.$

the overall cost of capital rises

c$.$

the overall cost of capital first rises, reaches a maximum, and then declines

d$.$

the overall cost of capital declines