The question asks to arrange specific substages of Piaget's sensorimotor stage in chronological order, from earliest to latest.

Understanding Sensorimotor Substages

Jean Piaget's theory describes cognitive development in stages. The sensorimotor stage (birth to ~2 years) is characterized by infants gaining knowledge through sensory experiences and physical actions.

Defining Key Substages

Let's define the relevant substages mentioned:

• I. Secondary circular reactions: Occurs roughly between 4 to 8 months. Infants begin to repeat pleasurable actions involving external objects.
• II. Coordination of secondary circular reactions: Typically observed from 8 to 12 months. Infants start combining schemes intentionally to achieve goals, showing early signs of goal-directed behavior.
• III. Mental representation: Develops towards the end of the sensorimotor stage, around 18 to 24 months. This involves the ability to form mental images or concepts of objects and events.
• IV. Tertiary circular reactions: Occurs approximately between 12 to 18 months. Infants experiment with new behaviors and explore the consequences of actions, showing curiosity and novelty.

Determining the Correct Sequence

The question requires arranging these substages from earliest to latest based on their typical age of occurrence.

Based on Piaget's established sequence, the correct order is:

1. III. Mental representation (approx. 18-24 months)
2. I. Secondary circular reactions (approx. 4-8 months)
3. II. Coordination of secondary circular reactions (approx. 8-12 months)
4. IV. Tertiary circular reactions (approx. 12-18 months)

This sequence corresponds to the provided correct answer, Option D.