Question: who is the author of the wealth of nations
[{'answer': 'Adam Smith', 'provenance': [{'wikipedia_id': '725991', 'title': 'The Wealth of Nations', 'start_paragraph_id': 1, 'start_character': 201, 'end_paragraph_id': 1, 'end_character': 211, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]