Question: when did bank of america buys merrill lynch
[{'answer': 'September 14 , 2008', 'provenance': [{'wikipedia_id': '33731299', 'title': 'Merrill Lynch', 'start_paragraph_id': 5, 'start_character': 540, 'end_paragraph_id': 5, 'end_character': 559, 'bleu_score': 1.0, 'section': 'Section::::History.:Sale to Bank of America.\n'}]}, {'provenance': [{'wikipedia_id': '33731299', 'title': 'Merrill Lynch', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 582, 'bleu_score': 0.9276281369144621, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 363896520158273596}, 'section': 'Section::::Abstract.'}]}]