问题
单项选择题
In a perfectly efficient market, portfolio managers should do all of the following EXCEPT:（）
A. rebalance their portfolio when changes are necessary.
B. diversify to eliminate systematic risk.
C. quantify their risk and return needs within the bounds of the client’s liquidity, income, time horizon, legal, and regulatory constraints.
答案
参考答案：B
解析：
Portfolio mangers cannot eliminate systematic risk (i. e. market risk) through the use of diversification. Portfolio managers should try to eliminate unsystematic portfolio risk.