为什么C不正确？

问题如下：

Which of the following is least likely to explain why the role of the chair of a company board is so important?

选项：

A.The chair sets the agenda for board discussions.

B.The chair helps ensure that all directors make their full contribution.

C.The chair will usually also be the CEO.

解释：

C is correct. Corporate governance has evolved away from the practice of combining the CEO and chair roles, because it leads to an excessive concentration of power in the individual holding the position and reduces the effectiveness of the board.