11. (3 points) John randomly picks four portfolios that are constructed by investing different weights in two stocks. The expected return and STD of these portfolios are given below. Portfolio Expectation Return Standard Deviation X 8% 20% Y 9% 24% Z 10% 22% W 11 % 27% Which of the following portfolios is definitely NOT on the efficient frontier? A) Portfolio X B) Portfolio Y. C) Portfolio Z. D) Portfolio W