Rita Buys a Super Grill Franchise

Rita buys a Super Grill franchise. Super Grill requires that its fran?chi?sees buy its products for every phase of their op?erations. Be?cause Rita wishes to buy less expensive products, she challenges the re?quirement. Her best argument is probably that the re?quirement violates

A) the commerce clause.
B) the Equal Protection Clause.
C) the federal antitrust laws.
D) the First Amendment.