Question: when was ac dc back in black released
[{'answer': '25 July 1980', 'provenance': [{'wikipedia_id': '196945', 'title': 'Back in Black', 'start_paragraph_id': 1, 'start_character': 92, 'end_paragraph_id': 1, 'end_character': 104, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]