Question: who plays the queen of thorns in game of thrones
[{'answer': 'Diana Rigg', 'provenance': [{'wikipedia_id': '42765829', 'title': 'Olenna Tyrell', 'start_paragraph_id': 3, 'start_character': 47, 'end_paragraph_id': 3, 'end_character': 57, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]