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, feature of the concrete operational theory is: \nSelect and explain. \nA. Animism and constructivism., B. Egocentrism., C. Symbolic play., D. All of the above.", 'role': 'user'}, {'content': 'Answer: B \nExplanation: • Animism and constructivism are seen in preoperational stage.\n• Ego-centrism is seen in concrete operation stage. ,\nNOTE: Symbolic play is seen in sensorimotor and pre-operational stage.', 'role': 'assistant'}]