Which of the following statements concerning Modern Portfolio Theory is (are) correct? 1. Portfolios located on the efficient frontier are preferable to all other portfolios in the feasible set. II. Portfolios falling to the left of the efficient frontier would be desirable if only they were possible. III. Beta is less useful in explaining a large portfolio's return fluctuations than an individual security's return fluctuations. IV. Portfolios C and X each have expected rates of return of 12%. C's beta is 0.9 and X's beta is 1.1, therefore C dominates X. O A. I only OB. I and III only OC. I, II and IV only OD. II and IV only