What is the Mean-Variance criterion? Use the Mean-Variance criterion to determine which of the following investments are efficient and which are inefficient? Investment Expected Return A B C D E F 5.30% 12.40% 14.63% 37.47% 7.90% 3.83% Standard Deviation of Returns 9.30% 11.49% 8.47% 9.40% 47.20% 1.25%