Question: where does the progesterone that helps maintain the pregnancy come from
[{'answer': 'the ovaries', 'provenance': [{'wikipedia_id': '66432', 'title': 'Progesterone', 'start_paragraph_id': 14, 'start_character': 464, 'end_paragraph_id': 14, 'end_character': 475, 'bleu_score': 1.0, 'section': 'Section::::Biological function.:Reproductive system.\n'}]}, {'answer': 'placenta', 'provenance': [{'wikipedia_id': '66432', 'title': 'Progesterone', 'start_paragraph_id': 21, 'start_character': 22, 'end_paragraph_id': 21, 'end_character': 30, 'bleu_score': 1.0, 'section': 'Section::::Biological function.:Reproductive system.\n'}]}, {'provenance': [{'wikipedia_id': '66432', 'title': 'Progesterone', 'start_paragraph_id': 90, 'start_character': 0, 'end_paragraph_id': 90, 'end_character': 626, 'bleu_score': 0.9792717993254391, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7531892270758236067}, 'section': 'Section::::Biochemistry.:Sources.:Animal.\n'}]}]