Question: when did arches national park become a national park
[{'answer': 'November 12 , 1971', 'provenance': [{'wikipedia_id': '18951296', 'title': 'Arches National Park', 'start_paragraph_id': 3, 'start_character': 155, 'end_paragraph_id': 3, 'end_character': 173, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '18951296', 'title': 'Arches National Park', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 230, 'bleu_score': 0.788489623903534, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14150718191330651808}, 'section': 'Section::::Abstract.'}]}]