Zonk Corp.

The following data pertains to Zonk Corp., a manufacturer of ball bearings $($dollar amounts in millions$)$:

Total assets

Interest$-$bearing debt

Average pre$-$tax borrowing cost

Common equity:

Book value

Market value

Income tax rate

Market equity beta

$$7,460$

$$4,334$

$10\mathrm{.}5\%$

$$2,950$

$$13,003$

$35\%$

$1\mathrm{.}13$

Determine the weight on debt capital that should be used to calculate Zonk's weighted$-$average cost of capital:

a$.25\mathrm{.}0\%$

b$.21\mathrm{.}7\%$

c$.58\mathrm{.}2\%$

d$.50\mathrm{.}0\%$