solve all parts with proper explanation

a. Find the inefficient portfolios from the table above. b. If you can borrow and lend at 6.5+x percent, which of the above portfolios is best? c. If an investor has a risk tolerance of a maximum of 25 percent, what is the most suitable portfolio assuming the investor cannot borrow or lend. d. Which portfolio is the best for the investor if he can borrow or lend at the risk-free rate of 6.5+x e. percent and a risk tolerance of 25 percent standard deviation