Omar has a portfolio of assets with $10\%$ invested in a risk$-$free asset, $60\%$ in Stock A$,$ and the remainder of the portfolio is invested in Stock B$.$ Omar's portfolio is as risky as the market. If Stock A has a beta of $0\mathrm{.}8,$ find the beta of Stock B in Omar's portfolio.

Group of answer choices

$1\mathrm{.}00$

$1\mathrm{.}24$

$1\mathrm{.}60$

$1\mathrm{.}73$