Question: where does the most expensive coffee bean come from
[{'answer': 'kopi luwak', 'provenance': [{'wikipedia_id': '756653', 'title': 'Kopi luwak', 'start_paragraph_id': 4, 'start_character': 9, 'end_paragraph_id': 4, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]