Question: what weight class did muhammad ali fight in
[{'answer': 'Heavyweight', 'provenance': [{'wikipedia_id': '63747', 'title': 'Muhammad Ali', 'start_paragraph_id': 9, 'start_character': 257, 'end_paragraph_id': 9, 'end_character': 268, 'bleu_score': 1.0, 'section': 'Section::::Early life and amateur career.\n'}]}]