Question: who holds the executive power of the united states
[{'answer': 'president', 'provenance': [{'wikipedia_id': '2015257', 'title': 'Powers of the president of the United States', 'start_paragraph_id': 0, 'start_character': 14, 'end_paragraph_id': 0, 'end_character': 23, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2015257', 'title': 'Powers of the president of the United States', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 401, 'bleu_score': 0.9669306597086381, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 920783871237554720}, 'section': 'Section::::Executive powers.\n'}]}]