A stock has a beta of $1\mathrm{.}8$ and an expected retum of $13\%$ from the stock market. If the risk$-$free rate is $3\%$ and market risk premium is $7\%,$ what is your conclusion on the stock valuation? $($Hint: use CAPM model$)$

a$.$ The stock is overvalued.

b$.$ The stock is undervalued.

c$.$ The stock is fairly$-$valued.

d$.$ Cannot be determined.