Question: who becomes new chief in grey's anatomy
[{'answer': 'Owen Hunt', 'provenance': [{'wikipedia_id': '31748634', 'title': "Grey's Anatomy (season 8)", 'start_paragraph_id': 2, 'start_character': 392, 'end_paragraph_id': 2, 'end_character': 401, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '31748634', 'title': "Grey's Anatomy (season 8)", 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 1041, 'bleu_score': 0.9730644290195721, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7753443662216628362}, 'section': 'Section::::Abstract.'}]}]