Question: who played nellie's husband on little house on the prairie
[{'answer': 'Tracy', 'provenance': [{'wikipedia_id': '25417613', 'title': 'Steve Tracy', 'start_paragraph_id': 0, 'start_character': 6, 'end_paragraph_id': 0, 'end_character': 11, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '25417613', 'title': 'Steve Tracy', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 381, 'bleu_score': 0.936655266249045, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12134607248748656770}, 'section': 'Section::::Biography.:Career.\n'}]}]