Question: who has appeared in the most fa cup finals
[{'answer': 'Arsenal', 'provenance': [{'wikipedia_id': '19887297', 'title': 'List of FA Cup Finals', 'start_paragraph_id': 3, 'start_character': 52, 'end_paragraph_id': 3, 'end_character': 59, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Manchester United'}]