Question: who played the gnome king in return to oz
[{'answer': 'Nicol Williamson', 'provenance': [{'wikipedia_id': '583407', 'title': 'Return to Oz', 'start_paragraph_id': 1, 'start_character': 141, 'end_paragraph_id': 1, 'end_character': 157, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]