Question: what does the e stand for in 4l60e
[{'answer': 'electronic', 'provenance': [{'wikipedia_id': '3616873', 'title': 'GM 4L60-E transmission', 'start_paragraph_id': 9, 'start_character': 102, 'end_paragraph_id': 9, 'end_character': 112, 'bleu_score': 1.0, 'section': 'Section::::4L60-E.\n'}]}, {'provenance': [{'wikipedia_id': '3616873', 'title': 'GM 4L60-E transmission', 'start_paragraph_id': 9, 'start_character': 0, 'end_paragraph_id': 9, 'end_character': 611, 'bleu_score': 0.760061410657022, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14797843177508435827}, 'section': 'Section::::4L60-E.\n'}]}]