Which of the Following Statements Would Be Represented by a Backward-Bending

Which of the following statements would be represented by a backward-bending labor supply curve?

A) A $50,000-a-year professor works more hours than a $20,000-a-year professor.
B) The CEO of a major computer manufacturer works more hours than the union workers.
C) The owners of a successful business work fewer days than their employees.
D) Hospital janitors work fewer hours than the chief of obstetrics.
E) High-ranking executives are more likely to work past 5:00 p.m. than middle-level managers.