Question: who scored the most goals against man utd
[{'answer': 'Arsenal', 'provenance': [{'wikipedia_id': '34781180', 'title': 'Manchester United F.C. league record by opponent', 'start_paragraph_id': 2, 'start_character': 237, 'end_paragraph_id': 2, 'end_character': 244, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]