Question: where is the iris located in the eye
[{'answer': 'the boundary of the pupil', 'provenance': [{'wikipedia_id': '86801', 'title': 'Iris (anatomy)', 'start_paragraph_id': 8, 'start_character': 69, 'end_paragraph_id': 8, 'end_character': 94, 'bleu_score': 1.0, 'section': 'Section::::Structure.\n'}]}]