B选项：在语法上，同一个代词的指代对象应相同。但在本选项中，them应指代benefits，而themselves应指代employees。
themselves--wordy, unclear; 'to themselves' modifies pick or most important of them;
you should have a second verb in (e) because the tense changes. in general, if you don't have a second verb, then the implication is that the tense doesn't change.
in standard english usage, "disturbing to X" is usually used only when X is a person whose sensibilities have been disturbed. so this sentence appears to imply that the time period itself was offended.
"have been" implies that those disturbances (or their effects) still continue to this day. that's not true - the sentence implies that the disturbance existed only in that time period - so the present perfect doesn't make sense.
扫描二维码，直接登录
B选项：在语法上，同一个代词的指代对象应相同。但在本选项中，them应指代benefits，而themselves应指代employees。
themselves--wordy, unclear; 'to themselves' modifies pick or most important of them;