Question: who wrote the letter that mrs. ansley believed was from mr. slade twenty years earlier
[{'answer': 'Alida', 'provenance': [{'wikipedia_id': '2959329', 'title': 'Roman Fever', 'start_paragraph_id': 3, 'start_character': 17, 'end_paragraph_id': 3, 'end_character': 22, 'bleu_score': 1.0, 'section': 'Section::::Plot summary.\n'}]}, {'provenance': [{'wikipedia_id': '2959329', 'title': 'Roman Fever', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 1048, 'bleu_score': 0.9892179350238061, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13932642533043094816}, 'section': 'Section::::Plot summary.\n'}]}]