$2)$ Suppose that we estimate a relationship between volatility, y in percent, and the number of stocks in a portfolio, x given by y $=55\mathrm{.}22\mathrm{.}0$x$.$ If a portfolio contains ten stocks, what would be the volatility to the nearest $1\%($e$.$g$.$ state $1\%$ for $0\mathrm{.}8\%)?$ A$)15\%$ B$)20\%$ C$)35\%$ D$)50\%$