问题如下：
Risk management of hedge funds has challenges not generally faced in traditional investment management companies. Which of the following statements are correct about hedge fund risk management?
I. Because hedge funds can hold long and short positions, and can use derivatives and leverage, their exposure to market risks can experience large and rapid changes that make it difficult to assess these exposures using only monthly returns.
II. Many hedge funds use over-the-counter derivatives, which are valued by models or quoted prices and often hold illiquid assets; as a result, the returns of these strategies generally exhibit much lower serial correlation than mutual fund returns.
III. For hedge fund strategies that use leverage to amplify returns and rely on their ability to move out of trades quickly when they turn against them, liquidity risk must be closely monitored and managed.
IV. Hedge fund returns are often similar to the return of a basket of exotic derivatives with nonlinear payoffs, and therefore assessing risk based on past performance can be misleading.
选项：
A.I，II，III，and IV
B.I，III，and IV
C.I and III
D.II and IV
解释：
B is correct. Statements I., III., and IV. are correct. Statement II. is false because illiquid assets create higher serial correlation.
why 第一条 only use monthly return 是正确的呢？ 有条件不能daily weekly吗？
