Question: who acted as the provisional president of the constituent assembly
[{'answer': 'Sachchidananda Sinha', 'provenance': [{'wikipedia_id': '1589530', 'title': 'Constituent Assembly of India', 'start_paragraph_id': 15, 'start_character': 4, 'end_paragraph_id': 15, 'end_character': 24, 'bleu_score': 1.0, 'section': 'Section::::Organization.\n'}]}, {'provenance': [{'wikipedia_id': '1589530', 'title': 'Constituent Assembly of India', 'start_paragraph_id': 24, 'start_character': 0, 'end_paragraph_id': 24, 'end_character': 292, 'bleu_score': 0.528743013349359, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6706253819212461867}, 'section': 'Section::::Time Line of Formation of "The Constitution of India".\n'}]}]