Question: what process of photosynthesis occurs in the stroma of the chloroplast
[{'answer': 'Calvin cycle', 'provenance': [{'wikipedia_id': '32721658', 'title': 'Stroma (fluid)', 'start_paragraph_id': 4, 'start_character': 101, 'end_paragraph_id': 4, 'end_character': 113, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '32721658', 'title': 'Stroma (fluid)', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 259, 'bleu_score': 0.8321448502360531, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4002146046188616506}, 'section': 'Section::::Abstract.'}]}]