What of the following best describe a cartel?

A cartel is a formal agreement between competing firms in an industry to coordinate their production, pricing, or marketing strategies to maximize profits and reduce competition. This often leads to higher prices for consumers and can limit the availability of goods or services. Cartels are typically illegal in many countries because they undermine free market principles and can lead to antitrust violations. Examples include OPEC in the oil industry and various price-fixing agreements in different sectors.