Answer:
b) preoperational
Explanation:
One of the famous psychologist Jean Piaget has proposed the theory of cognitive development in which he has mentioned four distinct stages.
Preoperational stage: This is the second stage in the theory of cognitive development and starts around the age of two years and lasts through the age of seven years. During this stage, a child learns to start talking, engage in symbolic play, as well as learn to manipulate different symbols.
In the question above, the statement signifies that children who were in the preoperational stage of development have incorrectly claimed about the given study because they haven't yet developed logic and reasoning as it occurs in the concrete operational stage.