For each of the following pairs of investments, indicate which would always be preferred by a rational investor (assuming that these are the only investments available to the investor): a.PortfolioAPortfolioBr=10bqr=6z=12z=12z PreferencePortfolioAPortfolioBIndeterminate b.PortfolioCPortfolioDr=11qr=9q=12z=6z c.PortfolioEPortfolioFr=16%r=16%=20%=14% Preference:PortfolioEPortfolioFIndeterminate