Which of the Following Is Not a Situation Under Which

Which of the following is not a situation under which men and women may be paid different wages under the Equal Pay Act?

A) When payment is made pursuant to a seniority system.
B) When payment is made pursuant to a merit system.
C) When payment is made pursuant to a system which measures earnings by quantity or quality of production.
D) When the differential is based on any factor other than sex.
E) When the parties sign a waiver.