Question: in the united states the president is the head of which branch of government
[{'answer': 'Executive branch', 'provenance': [{'wikipedia_id': '195149', 'title': 'Federal government of the United States', 'start_paragraph_id': 34, 'start_character': 11, 'end_paragraph_id': 34, 'end_character': 27, 'bleu_score': 1.0, 'section': 'Section::::Legislative branch.:Powers of Congress.:Congressional oversight.\n'}]}]