Darla graduated from college four years ago and has been working at Cascades Corp. ever since. She has always received praiseworthy performance ratings based on the quality of her work. In the past week, she learned that her organization hired a recent college graduate with no experience and are paying her more money than they are paying Darla. Which of the following theories will Darla likely use to evaluate this situation? Expectancy theory Self-determination theory Work design theory Equity theory