You have the following data: rRF $=3\mathrm{.}00\%$; RPM $=4\mathrm{.}50\%$; and b $=1\mathrm{.}00.$ What is the cost of equity from retained earnings based on the CAPM approach?

a$.$

$7\mathrm{.}50\%$

b$.$

$4\mathrm{.}50\%$

c$.$

$7\mathrm{.}85\%$

d$.$

$7\mathrm{.}00\%$