A highly risk-averse investor is considering adding one additional stock to a three-stock portfolio, to form a four-stock portfolio. The three stocks currently held all have b=1.0 and a perfect positive correlation with the market. Potential new Stocks A and B both have expected returns of 15%, and both are equally correlated with the market, with r=0.75. However, Stock A's standard deviation of returns is 12% versus 8% for Stock B. Which stock should this investor add to his or her portfolio, or does the choice matter