Could you give me the only answer simply, please?

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. Portfolio A Portfolio B r = 16% r = 12% o = 18% 0 = 18% Preference Portfolio A Portfolio B O Indeterminate b. Portfolio C Portfolio D r = 13% = 11% a a 16% = 6% Preference: Portfolio C Portfolio D O Indeterminate c. Portfolio E Portfolio F r = 16% r = 16% 0 = 18% = 12 Preference: Portfolio E Portfolio F O Indeterminate 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. Portfolio A Portfolio B r = 16% r = 12% o = 18% 0 = 18% Preference Portfolio A Portfolio B O Indeterminate b. Portfolio C Portfolio D r = 13% = 11% a a 16% = 6% Preference: Portfolio C Portfolio D O Indeterminate c. Portfolio E Portfolio F r = 16% r = 16% 0 = 18% = 12 Preference: Portfolio E Portfolio F O Indeterminate