Question: when did kentucky fried chicken start getting called kfc
[{'answer': 'March 1991', 'provenance': [{'wikipedia_id': '40483571', 'title': 'History of KFC', 'start_paragraph_id': 37, 'start_character': 3, 'end_paragraph_id': 37, 'end_character': 13, 'bleu_score': 1.0, 'section': 'Section::::Acquisition by PepsiCo.:International growth and franchisee disputes under John Cranor III.\n'}]}, {'provenance': [{'wikipedia_id': '40483571', 'title': 'History of KFC', 'start_paragraph_id': 37, 'start_character': 0, 'end_paragraph_id': 37, 'end_character': 872, 'bleu_score': 0.985764216565234, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3451902803925912335}, 'section': 'Section::::Acquisition by PepsiCo.:International growth and franchisee disputes under John Cranor III.\n'}]}]