Question: where are the most of the members of opec located
[{'answer': 'Middle Eastern', 'provenance': [{'wikipedia_id': '166346', 'title': 'OPEC', 'start_paragraph_id': 40, 'start_character': 158, 'end_paragraph_id': 40, 'end_character': 172, 'bleu_score': 1.0, 'section': 'Section::::History and impact.:1959–1960 anger from exporting countries.\n'}]}, {'provenance': [{'wikipedia_id': '166346', 'title': 'OPEC', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 679, 'bleu_score': 0.6577374553195381, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4947963189480895089}, 'section': 'Section::::Abstract.'}]}]