Question: who discovered the advantages of ac over dc
[{'answer': 'Westinghouse Electric Company', 'provenance': [{'wikipedia_id': '342086', 'title': 'War of the currents', 'start_paragraph_id': 16, 'start_character': 343, 'end_paragraph_id': 16, 'end_character': 372, 'bleu_score': 1.0, 'section': 'Section::::Background.:Westinghouse enters the AC business.\n'}]}]