Horizontal Price-Fixing Occurs When

Horizontal price-fixing occurs when:

A) one or more companies charge the same prices for goods at all their stores for an unreasonable length of time
B) a manufacturer requires its independent dealers to sell its products at a given price
C) a company with the entire market on a patented product sells the product at a fixed price
D) two or more competing companies agree on the prices to charge for their products
E) prices are determined with reference to an index,such as the average price of crude oil,which neither the seller nor the purchaser can control