Question: when was the first meeting of constitution assembly held
[{'answer': '6 December 1946', 'provenance': [{'wikipedia_id': '1589530', 'title': 'Constituent Assembly of India', 'start_paragraph_id': 23, 'start_character': 12, 'end_paragraph_id': 23, 'end_character': 27, 'bleu_score': 1.0, 'section': 'Section::::Time Line of Formation of "The Constitution of India".\n'}]}]