Callan is risk-averse and hold a well-diversified investment portfolio. Callan is considering adding one (and only one) additional stock to his portfolio. Assume that all new stocks have the same expected returns of 8.5% and that the returns are sufficient to compensate for risk. Which stock should Callan add to his portfolio?

a.one with the smallest standard deviation. b.additional information needed. c.one with the highest required return. d.they should be indifferent as the expected returns are the same. e.one with the smallest beta