Concept:OPEC is a major international body for petroleum-exporting countries, and knowing its central headquarters is a basic fact in economics.
Explanation:The Organization of Petroleum Exporting Countries (OPEC) helps its member nations coordinate crude oil output and pricing policies.
OPEC operates mainly through an executive body known as the OPEC Secretariat.
Under the provisions of the OPEC Statute, this Secretariat is recognized as the official headquarters of the Organization.
This headquarters is situated in the city of Vienna, the capital of Austria.
Hence, the correct choice is the option that names Vienna, Austria, not Paris, Geneva, or Lagos.
Answer:Option
D: Vienna, Austria.