Question: what does ac dc stand for in the rock band
[{'answer': 'alternating current / direct current', 'provenance': [{'wikipedia_id': '149225', 'title': 'AC/DC', 'start_paragraph_id': 9, 'start_character': 181, 'end_paragraph_id': 9, 'end_character': 216, 'bleu_score': 1.0, 'section': 'Section::::History.:Background and name.\n'}]}, {'provenance': [{'wikipedia_id': '149225', 'title': 'AC/DC', 'start_paragraph_id': 9, 'start_character': 0, 'end_paragraph_id': 9, 'end_character': 657, 'bleu_score': 0.9823771291847391, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10906406181565514455}, 'section': 'Section::::History.:Background and name.\n'}]}]