Question: who is the highest ranking officer in the navy
[{'answer': 'admiral', 'provenance': [{'wikipedia_id': '10656648', 'title': 'List of United States Navy four-star admirals', 'start_paragraph_id': 0, 'start_character': 37, 'end_paragraph_id': 0, 'end_character': 44, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '10656648', 'title': 'List of United States Navy four-star admirals', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 289, 'bleu_score': 0.9603762111511761, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18027265914561956358}, 'section': 'Section::::Abstract.'}]}]