Early childhood development in education encompasses development from:

Early childhood development in education is generally recognized as encompassing the period from birth to age eight. This timeframe is critical because it covers the most formative years in a child's life, during which significant cognitive, emotional, social, and physical development occurs.

Research in child development highlights that experiences and learning during these early years lay the foundation for future growth and learning. Birth to age eight includes various developmental milestones, from the establishment of basic motor skills and language development in infants to initial academic abilities and social skills as children prepare for and enter primary school.

The other options present a narrower focus. For instance, the period from birth to one year only captures the initial phase of development, which, while important, does not include the subsequent growth that occurs through early childhood. Focusing solely on preschool years to the end of primary grades ignores the early formative experiences and the vital learning that happens prior to formal schooling. Lastly, the range from first word to formal operational thought in adolescence delineates stages of cognitive development but extends too far into adolescence, which is outside the typical educational focus for early childhood professionals. Therefore, the comprehensive view encapsulated in the first choice is vital for understanding early childhood education.