b. objective function

c. constraint

4 A financial advisor is about to build an investment portfolio for a client who has $100,000 to invest. The four investments available are A, B, C, and D. Investment A will earn 4 percent. B earns 6 percent; C carns 9 percent; and D earns 12 percent. The client has put the following conditions on the investments: A is to be no more than one-half of the total invested. A cannot be less than 30 percent of the total investment. C cannot be less than D. Identify the decision variables of this problem. Write out the objective function and constraints. (a) Decision variables (2 points)