Question: who was the king who signed the magna carta
[{'answer': 'King John of England'}, {'provenance': [{'wikipedia_id': '20958', 'title': 'Magna Carta', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 841, 'bleu_score': 0.512319892272447, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4740016416162968129}, 'section': 'Section::::Abstract.'}]}]