Question: the medium of the artwork that decorates the sistine chapel ceiling is
[{'answer': 'fresco', 'provenance': [{'wikipedia_id': '734692', 'title': 'Sistine Chapel ceiling', 'start_paragraph_id': 2, 'start_character': 126, 'end_paragraph_id': 2, 'end_character': 132, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '734692', 'title': 'Sistine Chapel ceiling', 'start_paragraph_id': 14, 'start_character': 0, 'end_paragraph_id': 14, 'end_character': 832, 'bleu_score': 0.985764216565234, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14736896837311702250}, 'section': 'Section::::Method.\n'}]}]