Concept:Infancy is the first stage of human development, spanning from birth to the end of the second year.
Explanation:Development is divided into stages: infancy, childhood, adolescence, and adulthood.
Infancy covers the first two years after birth.
During this period, a child grows rapidly and learns basic skills like sitting, crawling, and standing.
Key milestones in infancy include babbling (language), smiling (emotional), attachment (social), rapid physical growth (weight doubles by 6 months and triples by 1 year), and early cognitive abilities.
The pre-childhood stage starts after infancy, at age 2 to 6 years.
Thus, the correct duration for infancy is from birth to 2 years.
Answer:Option A: birth to 2 yr