What is the highest risk$-$to$-$reward ratio for the following stocks? $($The risk$-$free rate is $3\%.)$ Stock A has a beta of $1\mathrm{.}5$ and an expected return of $15\%.$ Stock B has a beta of $1\mathrm{.}8$ and an expected return of $23\%.$ Stock C has a beta of $\mathrm{.}9$ and an expected return of $14\%.$

$10\mathrm{.}45\%$

$8\mathrm{.}0\%$

$12\mathrm{.}22\%$

$11\mathrm{.}11\%$

$13\mathrm{.}25\%$