Question: where does the term ten four come from
[{'answer': 'APCO Ten Signals', 'provenance': [{'wikipedia_id': '208349', 'title': 'Ten-code', 'start_paragraph_id': 11, 'start_character': 23, 'end_paragraph_id': 11, 'end_character': 39, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '208349', 'title': 'Ten-code', 'start_paragraph_id': 11, 'start_character': 0, 'end_paragraph_id': 11, 'end_character': 1057, 'bleu_score': 0.9528971417446721, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11541541871538994593}, 'section': 'Section::::History.\n'}]}]