The risk-free rate, average returns, standard deviations, and betas for three funds and the S&P 500 are given below:

Fund Average Standard deviations Betas

A ) 13.5% 26.5% 1.05

B) 20% 30% 1.3

c) 16% 23% 1.10

S&P 12% 17% 1.00

risk free rate = 3%

if this makes up a well diversified portfolio, then ______ portfolio is preferred.