Scanlon Inc.$\text{'}$s CFO hired you as a consultant to help her estimate the cost of capital. You have been provided with the following data: $rRF=4\mathrm{.}10\%$;$RPM=5\mathrm{.}20\%$; and $b=0\mathrm{.}70.$ Based on the CAPM approach, what is the cost of equity from retained earnings?

$.10\mathrm{.}00\%$

b$.8\mathrm{.}07\%$

c$.9\mathrm{.}30\%$

d$.6\mathrm{.}51\%$

e$.7\mathrm{.}74\%$