3. Suppose that there are N assets whose returns are jointly normally distributed. Also, portfolios A and B are frontier portfolios, and that they are characterized as follows: A=0.2,A=0.1,B=0.3,B=0.2 and AB=0.25. Now answer the following question. a. What is the expected return and the variance of the return on the minimum variance portfolio? b. Argue if portfolio A is an efficient portfolio or not. c. What should be the variance of the efficient portfolio with an expected return of 0.25