This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': "According to Piaget's Cognitive theory, the sequence of development has been categorized as: \nSelect and explain. \nA. Sensorimotor stage, preoperational stage, concrete operational stage, formal operational stage., B. Sensorimotor stage, preoperational stage, formal operational stage, concrete operational stage., C. Pre-operational stage, sensorimotor stage, formal operational stage, concrete operational stage., D. Formal operational stage, preoperational stage, sensorimotor stage, concrete operational stage.", 'role': 'user'}, {'content': 'Answer: A \nExplanation: According to\xa0Piaget,\xa0 the ages\xa0between\xa06\xa0and 12\xa0roughly approximate\xa0the third\xa0 major\xa0developmental stage of cognition, that is, the phase of concrete\xa0operations.\xa0Piaget\xa0proposed\xa0 the\xa0following\xa0four\xa0major\xa0periods\xa0of intellectual\xa0development:\n\nSensorimotor:\xa0Birth\xa0to\xa018\xa0months\nPreoperational: 18\xa0months to\xa07 years\nConcrete operational:\xa07 to\xa012 years\nFormal operational:\xa012\xa0years\xa0and\xa0onward.\n\nPediatric Dentistry Infancy Through Adolescence Fourth Edition P: 469', 'role': 'assistant'}]