Question: what is the highest selling album of all time
[{'answer': 'Thriller', 'provenance': [{'wikipedia_id': '3329753', 'title': 'List of best-selling albums', 'start_paragraph_id': 4, 'start_character': 19, 'end_paragraph_id': 4, 'end_character': 27, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]