Question: when did the first ever mcdonald's open
[{'answer': 'December 12 , 1948', 'provenance': [{'wikipedia_id': '5671742', 'title': "History of McDonald's", 'start_paragraph_id': 4, 'start_character': 696, 'end_paragraph_id': 4, 'end_character': 714, 'bleu_score': 1.0, 'section': 'Section::::Early history.\n'}]}, {'provenance': [{'wikipedia_id': '5671742', 'title': "History of McDonald's", 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 713, 'bleu_score': 0.9825310706027971, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 720094240136953183}, 'section': 'Section::::Early history.\n'}]}]