Question: what is the legal voting age in the us
[{'answer': 'eighteen years old', 'provenance': [{'wikipedia_id': '70136', 'title': 'Twenty-sixth Amendment to the United States Constitution', 'start_paragraph_id': 1, 'start_character': 233, 'end_paragraph_id': 1, 'end_character': 251, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]