According to Research, When Will a Company's Employees Be MOST

According to research, when will a company's employees be MOST likely to help one another out and speak well of their jobs?

A) When they think that the rules at work are fair and respectful
B) When they think that they are being paid more than other people (regardless of how much they are actually being paid)
C) When they think that they are being paid a lot (regardless of what other people are being paid)
D) When they think that they are less skilled/capable than their fellow employees