The first stage of Piaget's cognitive-developmental theory is the sensorimotor stage, typically from birth to age two, where knowledge comes from physical interaction.

• A. Preoperational stage
• B. Sensorimotor stage
• C. Concrete operational stage
• D. Formal operational stage

Answer: (B)

Learning comes through acting on the world and sensing the results. In this stage, infants start with reflexes and progressively coordinate actions to explore objects, leading to more purposeful behavior. They build understanding by manipulating what they see and feel, and over time develop object permanence—the idea that things exist even when not visible. Language and abstract thinking aren’t the primary tools yet; thinking is closely tied to concrete actions and sensory experiences. The other stages move toward symbolic thought (preoperational), then logical operations on concrete objects (concrete operational), and finally abstract reasoning (formal operational). Because this description emphasizes knowledge gained through physical interaction and concrete actions in early infancy, it aligns with the sensorimotor stage.