Question: what sector of the u.s. economy consumes the greatest percentage of petroleum
[{'answer': 'Transportation', 'provenance': [{'wikipedia_id': '7635170', 'title': 'Energy in the United States', 'start_paragraph_id': 16, 'start_character': 192, 'end_paragraph_id': 16, 'end_character': 206, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]