Question: who plays merlin in the new king arthur movie
[{'answer': 'Charlie Hunnam', 'provenance': [{'wikipedia_id': '43679538', 'title': 'King Arthur: Legend of the Sword', 'start_paragraph_id': 1, 'start_character': 192, 'end_paragraph_id': 1, 'end_character': 206, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]