Question: who plays prince charles in reign season 3
[{'answer': 'Spencer MacPherson', 'provenance': [{'wikipedia_id': '52138605', 'title': 'Reign (season 3)', 'start_paragraph_id': 21, 'start_character': 12, 'end_paragraph_id': 21, 'end_character': 30, 'bleu_score': 1.0, 'section': 'Section::::Cast and characters.:Recurring.\n'}]}]