Question

1. which of the following is illegal under u.s. antitrust laws?

advertising products
offering sales promotions
firms competing for customers
competitors agreeing to fix prices

Explanation:

U.S. antitrust laws aim to promote fair competition. Advertising products, offering sales promotions, and firms competing for customers are normal business activities that enhance competition. However, competitors agreeing to fix prices is a form of collusion. Collusion reduces competition as it eliminates price - based rivalry among firms. This is illegal under U.S. antitrust laws as it harms consumers by preventing them from getting the benefits of competitive pricing.

Answer:

Competitors agreeing to fix prices