Which ability is associated with the concrete operational stage?

• A. Abstract Hypothetical Reasoning
• B. Mastery of Formal Logic
• C. Egocentrism
• D. Ability to Classify Objects Into Different Sets

Answer: (D)

In the concrete operational stage, children begin to think logically about concrete objects and can organize information in more systematic ways. A key skill is classification: they can group objects into different sets and understand that items can belong to multiple categories or hierarchies (for example, sorting by color or shape and recognizing invariants within those groupings). This reflects decentration and the ability to apply logical operations to tangible content, unlike earlier egocentric or magical thinking. Abstract hypothetical reasoning and mastery of formal logic require thinking beyond concrete objects and emerge in the next stage, while egocentrism is more characteristic of the earlier preoperational stage. So the best fit is the ability to classify objects into different sets, signaling improved logical organization in the concrete operational period.