Question: who was the last american soldier killed in vietnam
[{'answer': 'Charles McMahon', 'provenance': [{'wikipedia_id': '1926550', 'title': 'Charles McMahon and Darwin Judge', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Darwin Lee Judge', 'provenance': [{'wikipedia_id': '1926550', 'title': 'Charles McMahon and Darwin Judge', 'start_paragraph_id': 1, 'start_character': 52, 'end_paragraph_id': 1, 'end_character': 68, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1926550', 'title': 'Charles McMahon and Darwin Judge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 287, 'bleu_score': 0.9611463610973231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2511754488764952741}, 'section': 'Section::::Abstract.'}]}]