Question: the largest source of electricity generation in pakistan
[{'answer': 'fossil fuel', 'provenance': [{'wikipedia_id': '19242589', 'title': 'Electricity sector in Pakistan', 'start_paragraph_id': 3, 'start_character': 806, 'end_paragraph_id': 3, 'end_character': 817, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]