Question: who led the team that challenged the separate but equal ruling
[{'answer': 'Thurgood Marshall', 'provenance': [{'wikipedia_id': '210031', 'title': 'Separate but equal', 'start_paragraph_id': 22, 'start_character': 532, 'end_paragraph_id': 22, 'end_character': 549, 'bleu_score': 1.0, 'section': 'Section::::Rejection.\n'}]}, {'provenance': [{'wikipedia_id': '210031', 'title': 'Separate but equal', 'start_paragraph_id': 23, 'start_character': 0, 'end_paragraph_id': 23, 'end_character': 736, 'bleu_score': 0.9518296712451301, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8386949633455348372}, 'section': 'Section::::Rejection.\n'}]}]