Question: who saved cooper and rachel at the river
[{'answer': 'Nathan', 'provenance': [{'wikipedia_id': '3599553', 'title': 'Nathan Scott', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 6, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3599553', 'title': 'Nathan Scott', 'start_paragraph_id': 19, 'start_character': 0, 'end_paragraph_id': 19, 'end_character': 997, 'bleu_score': 0.988857503993915, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7023142435460597242}, 'section': 'Section::::Character arc.:Season 3.\n'}]}]