An investor wants to determine the safest way to structure a portfolio from several investments. investment a produces anaverage annual return of 14% with a variance of 0025. investment b produces an average rate of return of 9% with avariance of 0.015. investment c produces an average rate of return of 8% with a variance of 0.010. investments a and bhave a covariance of 28, and investmentsa and c have a covariance of —0.006. investments b and c have acovariance of 0.00125.a. suppose the investor wants to achieve at least a 12% return. what is the least risky way of achieving this goal? b. suppose the investor regards risk minimization as being five times more important than maximizing return. whatportfolio would be most appropriate for the investor.)