You have been managing a $4 million portfolio that has a beta of 1.5 and a required rate of return of 13%. The current risk-free rate is 5.5%. Assume that you receive another $1 million. If you invest the money in a stock with a beta of 1.75, what will be the required return on your $5 million portfolio? a. 10.75% b. 11.50% c. 12.25% d. 12.75% 13.25% e