Question: tax implemented to curb the carbon emission of cars and pollutants by factories
[{'answer': 'carbon tax', 'provenance': [{'wikipedia_id': '84107', 'title': 'Carbon tax', 'start_paragraph_id': 1, 'start_character': 2, 'end_paragraph_id': 1, 'end_character': 12, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]