Which of the Following Statements About the Robinson-Patman Act Is

Which of the following statements about the Robinson-Patman Act is True?

A) According to the act, quantity discounts are the only kind of discount that is always permissible in interstate trade.
B) Under this act, the buyer is as guilty as the seller if the buyer knowingly receives an unlawful price discrimination.
C) The act only applies to intrastate activities.
D) All price differentials are illegal according to this act.
E) The act applies to sales made to middlemen and to ultimate consumers.