Which of the Following Is an Example of What Equity

Which of the following is an example of what equity theory refers to as an external comparison?

A) Ashley is guilty because she found out she will be beating out her best friend, Morgan, for a promotion.
B) Bailey is angry because she finds out that dental hygienists in other offices earn more than she does.
C) Emmi thinks the other two receptionists in her office get longer lunches than she does.
D) Syd often calls other dentists to ask where to get supplies for the best price.
E) Marci feels like she is probably the least skilled player in the city orchestra.