Question: what is the primary basis for the economy of saudi arabia
[{'answer': 'oil', 'provenance': [{'wikipedia_id': '27273', 'title': 'Economy of Saudi Arabia', 'start_paragraph_id': 1, 'start_character': 102, 'end_paragraph_id': 1, 'end_character': 105, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]