Olivia understands her world primarily by grasping and sucking easily available objects. Olivia is clearly in Piaget's ______ stage.

The correct choice reflects a fundamental stage in Jean Piaget's theory of cognitive development known as the sensorimotor stage. This stage occurs from birth to approximately two years of age and is characterized by infants learning through their senses and motor activities. In this period, children like Olivia are actively exploring their environment by engaging in actions such as grasping, sucking, and manipulating objects. This hands-on experience is crucial for their cognitive growth, as they begin to understand their world through physical interaction rather than abstract thinking.

The focus on sensory and motor functions is what sets this stage apart from others in Piaget's framework. As children progress to later stages, such as preoperational, concrete operational, and formal operational, they start to develop more complex thoughts, including symbolic thinking, logical reasoning, and abstract concepts. However, during the sensorimotor stage, the learning is predominantly immediate and concrete, rooted in direct physical experiences.