Question: blue baby syndrome disease is caused due to
[{'answer': 'cyanotic heart disease', 'provenance': [{'wikipedia_id': '729431', 'title': 'Blue baby syndrome', 'start_paragraph_id': 2, 'start_character': 12, 'end_paragraph_id': 2, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'methemoglobinemia', 'provenance': [{'wikipedia_id': '729431', 'title': 'Blue baby syndrome', 'start_paragraph_id': 8, 'start_character': 79, 'end_paragraph_id': 8, 'end_character': 96, 'bleu_score': 1.0, 'section': 'Section::::Causes.:Nitrates.\n'}]}]