Question: who is the chair of the green party
[{'answer': 'Green National Committee', 'provenance': [{'wikipedia_id': '30696', 'title': 'Green Party of the United States', 'start_paragraph_id': 51, 'start_character': 11, 'end_paragraph_id': 51, 'end_character': 35, 'bleu_score': 1.0, 'section': 'Section::::Structure and composition.:Committees.\n'}]}]