Question: who holds the record for the most rebounds in the nba
[{'answer': 'Wilt Chamberlain', 'provenance': [{'wikipedia_id': '10090161', 'title': 'List of National Basketball Association single-game rebounding leaders', 'start_paragraph_id': 2, 'start_character': 22, 'end_paragraph_id': 2, 'end_character': 38, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]