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
Object permanence seen in which stage of Jean Piaget’s theory 
Select and explain. 
A. Sensorimotor, B. Pre-operational stage, C. Concrete operations stage, D. Formal operations stage
A: Sensorimotor
Answer: A: Sensorimotor 
Explanation: None