The headquarter of the Organization of Petroleum Exporting Countries are at

The correct answer is D. Vienna.

The Organization of the Petroleum Exporting Countries (OPEC) is an intergovernmental organization of 13 oil-producing countries headquartered in Vienna, Austria. OPEC was founded in 1960 in Baghdad by five countries: Iran, Iraq, Kuwait, Saudi Arabia, and Venezuela. The organization’s stated mission is to “coordinate and unify the petroleum policies of its Member Countries and ensure the stabilization of oil markets in order to secure an efficient, economic and regular supply of petroleum to consumers, a fair return on investments and a steady income to the producing countries.”

Algeria, Lagos, and Kuwait are all members of OPEC, but their headquarters are not in Vienna.