According to research published in Organizational Behavior magazine

Which of the following best completes the passage below?
According to research published in Organizational Behavior magazine, managers in large firms tend to produce quite similar evaluations of their employees, thus employees who do not outperform their targets are expected to receive virtually identical and minimal annual raises. Hence, according to this research, it can be expected that ______________.

A) employees in large firms, who were ranked quite similar by their manager, will receive substantially different annual raises. - Incorrect, question states that employees who are rated similar (who do not outperform their targets) all get minimal increase - so the answer choice violates that.
B) in small firms, the raises given to higher-ranked employees will be significantly higher than those of their colleagues in the firm. - Incorrect. The answer choice is out of scope. Argument does not talk about small firms.
C) average-ranked employees in large firms will work harder in order to get more than the minimal raise. - Correct. Arguments states that if employees do not outperform they will get minimal raise. Now to not get minimal raise they need to outperform their targets. Hence they will work harder.
D) managers will give the higher raises to employees with significantly higher salaries. - Incorrect Argument does not talk about hike based on salaries.
E) Managers in large firms will be motivated to raise their own evaluations, in order to get higher salary raises. - Incorrect Argument does not talk about managers raising their own evaluations. Infact it can be interpreted that managers will be evaluated by their managers.