Question: the spleen is part of what system in the human body
[{'answer': 'immune system', 'provenance': [{'wikipedia_id': '42567', 'title': 'Spleen', 'start_paragraph_id': 2, 'start_character': 85, 'end_paragraph_id': 2, 'end_character': 98, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '42567', 'title': 'Spleen', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 522, 'bleu_score': 0.9159317989197081, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14410735768514374346}, 'section': 'Section::::Abstract.'}]}]