Answer: C) Lisa starts working longer hours after learning that her co-workers earn less than she does for the same work.
Step-by-step explanation:
The Equity Theory was posited by John Stacey Adams in 1963 and it argued that 2 key components in motivating employees are fairness and equity. This means that employees are more motivated when they feel they have getting the same outputs as their relevant colleagues for the inputs they put in if those inputs are the same as their relevant colleagues as well. If employees have reason to believe that there is no fairness in output, they will adjust their input to match the level of Equity they believe in. This is what Megan did by starting to reduce her productivity in response to not getting the same salary.
Lisa also subscribes to this theory because she saw that she was getting more output for the same amount of input as others. She therefore adjusted her input to be more than theirs so that the output she received would be fairer.