Question: who did the voice of frosty the snowman
[{'answer': 'Jackie Vernon', 'provenance': [{'wikipedia_id': '8280952', 'title': 'Frosty the Snowman (film)', 'start_paragraph_id': 1, 'start_character': 670, 'end_paragraph_id': 1, 'end_character': 683, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]