Calculate the required rate of return for Climax Inc., assuming that $(1)$ investors expect a $4\mathrm{.}0\%$ rate of inflation in the future, $(2)$ the real risk$-$free rate is $2\mathrm{.}8\%,(3)$ the market risk premium is $4\mathrm{.}5\%,(4)$ the firm has a beta of $1\mathrm{.}90,$ and $(5)$ its realized rate of return has averaged $15\mathrm{.}0\%$ over the last $5$ years. Do not round your intermediate calculations.

a$.12\mathrm{.}55\%$

b$.11\mathrm{.}30\%$

c$.21\mathrm{.}47\%$

d$.15\mathrm{.}35\%$

e$.11\mathrm{.}35\%$