Question: who has the worst era in mlb history
[{'answer': 'Philadelphia Athletics', 'provenance': [{'wikipedia_id': '5282135', 'title': 'List of worst Major League Baseball season records', 'start_paragraph_id': 25, 'start_character': 4, 'end_paragraph_id': 25, 'end_character': 26, 'bleu_score': 1.0, 'section': 'Section::::Other teams.\n'}]}]