Answer:
The correct answer is b.) Jean Piaget's theory of cognitive development
Explanation:
Jean Piaget's theory of cognitive development is a psychological theory about children cognitive development divided in four stages it focuses in how children acquire knowledge and the nature of their intelligence and it's primarily divided by ages, going from 2 years old with the sensorimotor stage, followed by preoperational age from ages two to seven and from seven up to eleven the stage known as Concrete operational state, which in Dr. Holiday's case is the one he is basing on his study and finally from twelve and up the formal operational stage. So Dr. Holiday beliefs are based on this theory because it explains the logic about concrete situations children experiences in those ages.
