Question: ct is produced by which cells of the thyroid gland
[{'answer': 'Parafollicular cells', 'provenance': [{'wikipedia_id': '30078', 'title': 'Thyroid', 'start_paragraph_id': 45, 'start_character': 99, 'end_paragraph_id': 45, 'end_character': 119, 'bleu_score': 1.0, 'section': 'Section::::Function.:Calcitonin.\n'}]}, {'provenance': [{'wikipedia_id': '30078', 'title': 'Thyroid', 'start_paragraph_id': 45, 'start_character': 0, 'end_paragraph_id': 45, 'end_character': 735, 'bleu_score': 0.9808590314834971, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4687175767341285643}, 'section': 'Section::::Function.:Calcitonin.\n'}]}]