Question: what is the file extension for adobe illustrator
[{'answer': '. ai'}, {'provenance': [{'wikipedia_id': '4891617', 'title': 'Adobe Illustrator Artwork', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 227, 'bleu_score': 0.9451524926983921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1600508948728440223}, 'section': 'Section::::Abstract.'}]}]