Sally earned a 10 percent increase in her salary and received the entire increase at the beginning of the year, with the stipulation that she would not leave the company in that year. Five months later, she quit her job and went to work for a competitor. She had to return the 10 percent payment she had received because she had violated a rule for:_________
A) lump-sum salary increase.
B) profit-sharing.
C) commission.
D) employee benefit.
E) wage compensation.

Since in the question it is mentioned that Sally earned an increase of 10% in her salary and received an overall rise at the starting of the year in case that she do not leave the company.

Now after five months she quit a job, work for a competitor due to which she had to pay back the 10% payment as she break the rule of increase in lump sum salary

Therefore the correct option is A.