Phillip Esten Operates a Mail Store in Which He Offers

Phillip Esten operates a mail store in which he offers various services such as packaging items for shipment, delivering items to overnight services, and a fax machine. Esten charges $4.00 for deliveries for one-time customers and $2.00 for deliveries for his account customers. Esten's prices:

A) are a violation of the Robinson-Patman Act.
B) are not covered under the Robinson-Patman Act.
C) constitute price discrimination.
D) None of the above