Question: who used the geocentric system to explain planetary motions
[{'answer': 'Aristotle', 'provenance': [{'wikipedia_id': '83754', 'title': 'Geocentric model', 'start_paragraph_id': 1, 'start_character': 385, 'end_paragraph_id': 1, 'end_character': 394, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Ptolemy', 'provenance': [{'wikipedia_id': '83754', 'title': 'Geocentric model', 'start_paragraph_id': 1, 'start_character': 419, 'end_paragraph_id': 1, 'end_character': 426, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '83754', 'title': 'Geocentric model', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 394, 'bleu_score': 0.8330072659426141, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2556567997454693321}, 'section': 'Section::::Abstract.'}]}]