Question: who plays erica hahn on grey's anatomy
[{'answer': 'Brooke Smith', 'provenance': [{'wikipedia_id': '11720323', 'title': 'Brooke Smith (actress)', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 12, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '11720323', 'title': 'Brooke Smith (actress)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 306, 'bleu_score': 0.9645876452711911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13453132276138009715}, 'section': 'Section::::Abstract.'}]}]