Marilyn Peck, the Manager of Human Resources Makes the Following

Marilyn Peck, the manager of human resources makes the following statement: "Our new incentive system is the best way to encourage high performance out of each employee. It specifies the things that employees should do and the results that will lead to rewards."
David Witt, a production manager, responds by saying: "You ignore a key issue: no matter what else is going on, employees will not be motivated if they do not feel that they are being treated fairly. Workers who feel that they are paid less than others for the same work will not feel that they are being treated fairly unless the organization provides some kind of persuasive justification. For example, Robin cannot possibly be motivated given that she is paid much less than Jonaki."
Witt's claim that Robin must be dissatisfied assumes which of the following?
Jonaki is aware of Robin's salary.
Most people in the organization would agree that Robin and Jonaki do comparable work.
Jonaki receives more favorable employee reviews than Robin does.
Robin has met all of the goals specified by the organization's incentive system.
Robin has not been provided with a persuasive justification for the difference in salary.