Question: what is the most expensive car sold at auction
[{'answer': 'Ferrari 250 GTO', 'provenance': [{'wikipedia_id': '21592991', 'title': 'List of most expensive cars sold at auction', 'start_paragraph_id': 2, 'start_character': 12, 'end_paragraph_id': 2, 'end_character': 27, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]