A firm has a weighted average cost of capital of $11\mathrm{.}73$ percent. The cost of equity is $15\mathrm{.}8$ percent and the pretax cost of debt is $7\mathrm{.}6$ percent. The tax rate is $21$ percent. What is the target debt$-$equity ratio?

Multiple Choice

$\mathrm{.}53$

$\mathrm{.}89$

$1\mathrm{.}87$

$1\mathrm{.}41$

$\mathrm{.}71$