The covariance of a particular stock with the market portfolio is $-0\mathrm{.}5.$ The variance of the stock is $0\mathrm{.}3.$ The variance of the market portfolio is $0\mathrm{.}5.$ Calculate the stock's Beta.

Question $12$ options:

$-2$

$0\mathrm{.}5$

$-1$

$-1\mathrm{.}87$