Based on the information, please answer the following:

i$)$ The cost of equity at $($D$/$E$)$ at $0\mathrm{.}11$ is $($ Show your detailed calculations$)$

a$)11\mathrm{.}00\%($approximately$)$

b$)11\mathrm{.}20\%($approximately$)$

c$)11\mathrm{.}30\%($approximately$)$

d$)11\mathrm{.}40\%($approximately$)$

ii$)$ At optimal capital structure, the equity $\%$ of the firm is $($ Show your detailed calculations$)$

a$)0\mathrm{.}8\%$

b$)0\mathrm{.}7\%$

c$)0\mathrm{.}6\%$

d$)0\mathrm{.}5\%$

iii$)$ WACC $($ weighted average cost of capital$)$ at the optimal capital structure is $($ Show your detailed calculations$)$

a$)10\mathrm{.}15\%$

b$)9\mathrm{.}75\%$

c$)10\mathrm{.}22\%$

d$)10\mathrm{.}18\%$