In Jean Piaget's theory of cognitive development, the Concrete Operational Stage (approx. 7–11 years) includes Conservation, Decentration, and Classification. When an 8-year-old child observes equal amounts of water in two identical glasses and recognizes that the volume remains unchanged after pouring one glass into a tall, narrow container, this cognitive ability primarily demonstrates which logical process?

Correct Answer: Option B (Reversibility & Decentration)

Cognitive Operations Explained:

• Conservation: The cognitive understanding that physical quantities (volume, mass, number) remain invariant despite perceptual transformations in shape or spatial arrangement.
• Reversibility: The mental ability to reverse an action mentally (e.g., realizing that pouring water back into the original glass restores its initial height).
• Decentration: Shifting attention away from a single focal dimension (height) to coordinate multiple dimensions simultaneously (height and width).
• Developmental Boundary: This operational logic functions effectively on concrete, tangible realities but does not yet extend to purely hypothetical abstractions.