Question: when did the mayan civilization reached its peak
[{'answer': 'The Classic period', 'provenance': [{'wikipedia_id': '18449273', 'title': 'Maya civilization', 'start_paragraph_id': 2, 'start_character': 1048, 'end_paragraph_id': 2, 'end_character': 1066, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '18449273', 'title': 'Maya civilization', 'start_paragraph_id': 21, 'start_character': 0, 'end_paragraph_id': 21, 'end_character': 665, 'bleu_score': 0.9796927878356411, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17111006934838073283}, 'section': 'Section::::History.:Classic period (c. 250–900 AD).\n'}]}]