You own two mutual funds. Fund A has a beta of $0\mathrm{.}7$ and Fund $B$ has a beta of $1\mathrm{.}3.$ If your portfolio beta is the same as the market portfolio, what proportion of your portfolio is invested in fund A$?$

$\frac{2}{3}$

$\frac{1}{3}$

$\frac{1}{2}$

$\frac{1}{4}$

$\frac{3}{4}$