Company A has a beta of $0\mathrm{.}70,$ while Company B$\text{'}$s beta is $1\mathrm{.}45.$ The required return on the stock market is $11\mathrm{.}00\%,$ and the risk$-$free rate is $2\mathrm{.}25\%.$ What is the difference between $A^{\text{'}}s$ and $B\text{'}$s required rates of return?

a$.4\mathrm{.}30\%$

b$.4\mathrm{.}71\%$

c$.5\mathrm{.}01\%$

d$.5\mathrm{.}06\%$