What marks the end of Piaget's sensorimotor period?

A) the achievement of object permanence
B) leaving behind egocentrism
C) conservation of number
D) the disappearance of reflexes

Object Permanence

The understanding, typically developed in infancy, that objects continue to exist even when they cannot be observed or heard.

Sensorimotor Period

In Piaget’s theory, the period of cognitive development from birth to about 2 years, in which the child has not yet achieved object permanence.

Egocentrism

A cognitive bias that makes an individual unable to understand or assume any perspective other than their own.