Question: who is widely credited with coining the term iron curtain
[{'answer': 'Winston Churchill', 'provenance': [{'wikipedia_id': '18953051', 'title': 'Iron Curtain', 'start_paragraph_id': 6, 'start_character': 264, 'end_paragraph_id': 6, 'end_character': 281, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '18953051', 'title': 'Iron Curtain', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 437, 'bleu_score': 0.919557221389063, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12535880209813436621}, 'section': 'Section::::Abstract.'}]}]