According to the graph below, which of the following is correct? Efficient Frontier . LE Select one: O a. Portfolio C is better than portfolio A because it has lower risk. O b. Only portfolio B is attainable. O c. A more risk-averse investor will prefer portfolios on the right side of the efficient frontier. O d. Portfolios on the upper segment above C dominate those on the bottom segment below C. Oe. Portfolio C is the tangency portfolio