Question: a b a c a b a is an example of which form from the classic period
[{'answer': 'rondo', 'provenance': [{'wikipedia_id': '200335', 'title': 'Rondo', 'start_paragraph_id': 2, 'start_character': 38, 'end_paragraph_id': 2, 'end_character': 43, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '200335', 'title': 'Rondo', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 908, 'bleu_score': 0.962364319094068, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1912447217446888026}, 'section': 'Section::::Form.\n'}]}]