Answer:
... acquired a mental operation.
Step-by-step explanation:
This question is aimed to examine the cognitive and physical development in middle childhood.
Congnitive has to do with the part of mental functions that deals with logic, as opposed to affective which deals with emotions.
Cognitive psychology is however the branch of psychology that examines internal mental processes such as problem solving, memory, and language.
Piaget helps us to understand that the operational ability of a child to reverse thought is due to their acquisition of mental operations. Piaget however saw children as making the journey of cognitive development alone.
And in the context above reversibility is defined through comparison
