Please help with this practice problem I am having difficulty with! Thank you in advance!

Asset A has an expected return of 18% and a standard deviation of 38%. Asset B has an expected return of 14% and a standard deviation of 21%. The correlation between asset A and B is-0.4. (a) (4 points) How much should you invest in asset A and asset B in order to obtain an expected return of 17%? (b) (8 points) Assuming you can borrow and lend at the risk-free rate of 8%, which asset (A or B) offers a better investment opportunity? Explain why. (c) (3 points) Can you construct a risk-free portfolio using only assets A and B, assuming you may short-sell either asset? If so, what are the weights of your portfolio. In not, briefly explain