Question: what type of blood does the pulmonary vein carry
[{'answer': 'oxygenated blood', 'provenance': [{'wikipedia_id': '601365', 'title': 'Pulmonary vein', 'start_paragraph_id': 1, 'start_character': 48, 'end_paragraph_id': 1, 'end_character': 64, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '601365', 'title': 'Pulmonary vein', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 281, 'bleu_score': 0.958740481558872, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3062262418938467348}, 'section': 'Section::::Abstract.'}]}]