Please explain too, thank you!

Please use the following information for this question. Assets Beta 0.6 1.9 Expected return 0.08 0.21 0.15 where "M" refers to the market portfolio, and all other assets not listed in the above table are fairly priced according to CAPM. The risk-free rate is 0.05. Which statement below about the optimal risky portfolio of an investor with mean-variance preference is true? Select one: A. In addition to the market portfolio, it should long on asset X and short on asset Y B. In addition to the market portfolio, it should short on asset X and long on asset Y C. In addition to the market portfolio, it should long on both asset X and asset Y D. In addition to the market portfolio, it should short on both asset X and asset Y E. It should include the market portfolio only, as 0.08 and 0.21 are fair expected returns for assets X and Y respectively