By the end of the sensorimotor stage, infants are capable of:

• A. Abstract reasoning about hypothetical situations.
• B. Symbolic thought, exploring objects by touch, and understanding object permanence.
• C. Mastery of formal mathematical reasoning.
• D. Language-based problem solving exclusively.

Answer: (B)

Understanding how infants think and learn during the sensorimotor stage helps explain what changes happen by its end. At this point, babies move from learning solely through direct actions to using mental representations and showing that objects exist even when they can’t see them. Symbolic thought—the ability to use signs, symbols, or imagined ideas—begins to emerge, and object permanence develops, meaning they understand that things continue to exist even when out of sight.

Exploring objects by touch and other actions stays a primary way they learn, so their behavior is still very much tied to physical interaction with the world. They’re not yet able to reason abstractly about hypothetical situations or master formal mathematical concepts, which appear later. Language and problem solving also aren’t the exclusive tools at this stage; knowledge is built through concrete interaction with their environment.