Please answer the questions about cartels and the specific case of OPEC. Which statement is generally true of cartels? Cartels never stick to their agreed‑upon quotas. Cartels usually raise prices by expanding output. Cartels collude to raise prices and profits. In the United States, cartel members can legally meet to set prices. Which statement is true of OPEC? OPEC includes only nations from the Middle East. OPEC agreements are enforced by international law. OPEC sets production quotas in order to restrict supply. The United States is a leading member of OPEC.