Question: where does most of earths oxygen come from today
[{'answer': 'photosynthetic organisms', 'provenance': [{'wikipedia_id': '24377796', 'title': 'Geological history of oxygen', 'start_paragraph_id': 1, 'start_character': 814, 'end_paragraph_id': 1, 'end_character': 838, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '24377796', 'title': 'Geological history of oxygen', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 2046, 'bleu_score': 0.9589382997138791, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10351600603675967755}, 'section': 'Section::::Abstract.'}]}]