Consider the two $($excess return$)$ index$-$model regression results for stocks A and $B.$ The risk$-$free rate over the period was $6\%,$ and the market's average return was $14\%.$ Performance is measured using an index model regression on excess returns.

b$.$ Which stock is the best choice under the following circumstances?

$\backslash$table$[[$i$.$ This is the only risky asset to be held by the investor.,Stock B$],[$ii$.$ This stock will be mixed with the rest of the investor's portfolio, currently composed solely of holdings in the market$-$index fund.,Stock B$],[$iii$.$ This is one of many stocks that the investor is analyzing to form an actively managed stock portfolio.,$]]$