9. Your uncle Bob has 50% of his wealth invested in Intel and another 50% invested in Apple. The beta of Apple is 1.4 and the beta of Intel is 1.8. Assume that the market portfolio return is 12% and its standard deviation is 18%, and also that the return on the risk free rate is 5%. What is the standard deviation of the efficient portfolio that delivers the same expected return than your Uncle's Bob portfolio? A. 20% B. 35% C. 22% D. 29% E. 15%