Question: who did the montgomery improvement association choose as its leader
[{'answer': 'Ralph Abernathy', 'provenance': [{'wikipedia_id': '2781370', 'title': 'Montgomery Improvement Association', 'start_paragraph_id': 1, 'start_character': 165, 'end_paragraph_id': 1, 'end_character': 180, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Martin Luther King , Jr.', 'provenance': [{'wikipedia_id': '2781370', 'title': 'Montgomery Improvement Association', 'start_paragraph_id': 4, 'start_character': 782, 'end_paragraph_id': 4, 'end_character': 806, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'answer': 'Edgar Nixon', 'provenance': [{'wikipedia_id': '2781370', 'title': 'Montgomery Improvement Association', 'start_paragraph_id': 1, 'start_character': 210, 'end_paragraph_id': 1, 'end_character': 221, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2781370', 'title': 'Montgomery Improvement Association', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 423, 'bleu_score': 0.9684940092844061, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 145751977226048305}, 'section': 'Section::::Abstract.'}]}]