Thaler & Co$.$ has the following capital stack: $$300M$ of debt, $$75M$ of preferred equity, and $$500M$ of common equity. If their after$-$tax cost of debt is $5\mathrm{.}5\%,$ their cost of preferred equity is $7\mathrm{.}1\%,$ and their cost of common equity is $18\mathrm{.}2\%,$ what is Thaler's weighted average cost of capital?

$11\mathrm{.}04\%$

$11\mathrm{.}72\%$

$12\mathrm{.}89\%$

$10\mathrm{.}27\%$

$14\mathrm{.}18\%$