Question: who becomes chief resident in grey anatomy season 7
[{'answer': 'April', 'provenance': [{'wikipedia_id': '27660054', 'title': 'April Kepner', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 5, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '27660054', 'title': 'April Kepner', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 991, 'bleu_score': 0.988919240064389, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7793742207219992926}, 'section': 'Section::::Storylines.\n'}]}]