Concept:Piaget's theory of cognitive development includes four stages, where the ability to solve problems using concrete objects is a hallmark of the Concrete Operational stage (ages 7-11).
Explanation:During the Concrete Operational stage, children think logically about tangible, real-world events.
They can manipulate objects mentally but only when they are physically present or have been directly experienced.
This stage follows the Pre-operational stage, where thinking is still egocentric and not yet logical.
Children at this stage master conservation, reversibility, and classification of objects.
Therefore, if a child can only solve problems using concrete objects, they are not yet capable of abstract or hypothetical reasoning, which is a feature of the later Formal Operational stage.
The other stages – Sensori-motor (infants learn through senses) and Pre-operational (preschoolers use symbols but lack logic) – do not involve systematic problem-solving with concrete objects.
Thus, the correct match is the Concrete Operational stage.
Answer:C. Concrete operational stage.