Final answer:
The members of OPEC have a common interest in maximizing profits related to oil exports, which classifies them as an economic region. They coordinate and unify their petroleum policies to stabilize oil markets, ensure a steady income for producers, and secure an efficient and economic supply of petroleum for consumers.
Step-by-step explanation:
The members of OPEC have a common interest in maximizing profits related to oil exports. This common interest classifies OPEC as an economic region. OPEC was formed in 1960 by oil-exporting nations, and its members seek ways to coordinate and unify their petroleum policies to stabilize oil markets, ensure a steady income for producers, and secure an efficient and economic supply of petroleum for consumers. One of the ways OPEC achieves its goals is by controlling oil production levels to influence oil prices in the global market.