Question: who plays the train conductor in polar express
[{'answer': 'Tom Hanks', 'provenance': [{'wikipedia_id': '3701905', 'title': 'The Polar Express (film)', 'start_paragraph_id': 1, 'start_character': 657, 'end_paragraph_id': 1, 'end_character': 666, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]