According to Piaget's theory of cognitive development, during the sensorimotor stage (from birth to about 2 years), the child's main developmental task is to do which of the following?

Introduction / Context:
Jean Piaget's theory of cognitive development describes how children's thinking changes through a series of stages. The first stage, called the sensorimotor stage, occurs from birth to about 2 years of age. Understanding the key cognitive achievements of each stage is important in developmental psychology and education. This question asks what the main developmental task is during the sensorimotor stage.

Given Data / Assumptions:

• The focus is on Piaget's sensorimotor stage (0 to about 2 years).
• Options describe different cognitive abilities such as logical operations, abstract reasoning, object permanence, moral reasoning, and symbolic language use.
• We assume familiarity with the general sequence of Piagetian stages: sensorimotor, preoperational, concrete operational, and formal operational.
• We must identify the ability specifically associated with the sensorimotor period.

Concept / Approach:
During the sensorimotor stage, infants learn about the world primarily through their senses (seeing, touching, hearing) and motor actions (grasping, sucking, reaching). One of the key milestones of this stage is the development of object permanence, the understanding that objects continue to exist even when they are out of sight. In later stages, children develop symbolic thinking (preoperational), logical operations and conservation (concrete operational), and abstract reasoning (formal operational). Complex moral reasoning also emerges later, not in infancy.

Step-by-Step Solution:
Step 1: Identify the age range of the sensorimotor stage: from birth up to about 2 years. Step 2: Recall that infants at this stage explore their environment by coordinating sensory inputs with motor actions, such as looking, touching, and mouthing objects. Step 3: Recognise that a critical achievement by the end of this stage is object permanence, demonstrated when a child searches for a toy that has been hidden from view. Step 4: Compare this with conservation of volume and number, which belongs to the concrete operational stage in older children. Step 5: Note that abstract thinking and hypothetical reasoning are features of the formal operational stage in adolescence. Step 6: Understand that complex moral reasoning develops gradually and is not a central task of infancy. Step 7: Conclude that the main task during the sensorimotor stage is the development of object permanence and coordination of sensory experiences with motor actions.

Verification / Alternative check:
Developmental psychology textbooks summarise Piaget's sensorimotor stage as a period when infants progress from reflex actions to goal directed behaviours and acquire object permanence. They often describe simple experiments like hiding a toy under a cloth and observing whether the infant searches for it. In contrast, they place conservation tasks (like pouring liquid into differently shaped containers) in the concrete operational stage and formal abstract reasoning in the formal operational stage. This clearly supports option C as the correct one.

Why Other Options Are Wrong:
Develop logical operations such as conservation of volume and number: This belongs to the concrete operational stage (around 7 to 11 years), not the sensorimotor stage. Achieve abstract thinking and formal hypothetical reasoning: Characteristic of the formal operational stage in adolescence, not of infants. Master complex moral reasoning about social rules and justice: Moral reasoning develops later and is not the primary focus of the sensorimotor stage. Use only language based symbols to think about the world: Symbolic thought and language usage expand greatly in the preoperational stage; infants at the sensorimotor stage rely more on action and perception.

Common Pitfalls:
Students sometimes mix up the achievements of different Piagetian stages, especially conservation tasks and abstract reasoning. Another error is to overestimate the cognitive abilities of infants and attribute advanced thinking to the sensorimotor stage. To keep the stages straight, remember: sensorimotor (senses and actions, object permanence), preoperational (symbols and language but limited logic), concrete operational (logical operations on concrete objects), and formal operational (abstract and hypothetical reasoning).

Final Answer:
During the sensorimotor stage, the main task is to develop object permanence and coordinate sensory experience with motor actions.