Question: who was the angel of death during ww2
[{'answer': 'Josef Mengele', 'provenance': [{'wikipedia_id': '84508', 'title': 'Josef Mengele', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 13, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]