再请问各位牛人另一题，拜托各位帮忙解惑阿~PP1-60

Because no employee wants to be associated with bad news in the eyes of a superior, information about serious problems at lower levels is progressively softened and distorted as it goes up each step in the management hierarchy. The chief executive is, therefore, less well informed about problems at lower levels
                    than
                are his or her subordinates at those levels.

The conclusion drawn above is based on the assumption that

(A) problems should be solved at the level in the management hierarchy at which they occur
(B) employees should be rewarded for accurately reporting problems to their superiors
(C) problem-solving ability is more important at higher levels than it is at lower levels of the management hierarchy
(D)chief executives obtain information about problems at lower levels from no source other than their subordinates
(E) some employees are more concerned about truth than about the way they are perceived by their superiors

答案是D
想请问一下这题题目我用颜色highlight起来的部份(than是否是要改成that阿?)
因为chief executive后面说的这段我一直翻得怪怪的...

还有，D选项是说："州长除了他的部属之外没有其它来源可以的道问题的信息"吗?

拜托帮忙解惑阿~谢谢!

拜托帮忙解惑阿~谢谢!