You Graduated from College Two Years Ago and Began Working

You graduated from college two years ago and began working at Hampstead Electronics. You have received good performance evaluations and a raise. You just found out that your organization has hired a recent college graduate with no experience at a higher salary than you are now making. You consider this an unfair act and resolve to do something about it.
-Which of the following theories best describes such a situation?

A) equity theory
B) two-factor theory
C) goal-setting theory
D) theory of needs
E) self-determination theory