Consider the single factor APT. Portfolio A has a beta of 1.3 and an expected return of 21%. Portfolio B has a beta of 0.7 and an expected return of 17%. Portfolio C has a beta of 1.5 and an expected return of 22%. The risk-free rate of return is 8%. If you wanted to take advantage of an arbitrage opportunity, you should take a short position in portfolio ________ and a long position in portfolio ________. a. C; B b. A; B c. B; C d. C; A e. A; C