Question: which explorer traveled to the carolinas and oklahoma and found the mississippi river
[{'answer': 'Hernando de Soto', 'provenance': [{'wikipedia_id': '52739', 'title': 'Hernando de Soto', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '52739', 'title': 'Hernando de Soto', 'start_paragraph_id': 1, 'start_character': 266, 'end_paragraph_id': 1, 'end_character': 515, 'bleu_score': 0.534981436602838, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5798195506709407208}, 'section': 'Section::::Abstract.'}]}]