6. Which of the following is not a common drawback of alternative investments? A. Alternative imvestments are relatively illiquid and thus requires a liquidity premium B. Usually have low correlation with stocks and bonds and thus can be used as a portfolio diversifier C. Some alternative investments are subject to the so-called "positive event risk" where amiable economic events would cause their price to rise D. High due diligence costs due to complex investment structures E. Difficulty to appraise performance as benchmark is hard to establish for alternative investments