Lifespan development.

• A. The study of growth, change, and stability from conception to death.
• B. Study of growth and changes only in childhood.
• C. The measurement of lifespan in hours.
• D. A theory that proposes people do not change after adolescence.

Answer: (A)

Life span development looks at how people grow, change, and remain the same across the entire life course, from conception to death. It covers physical, cognitive, and social-emotional development and includes the idea that some traits stay relatively stable even as new skills emerge. This perspective matters because it ties together early experiences, development over time, and how factors like environment and biology shape trajectories throughout life. The other options are narrower or incorrect: studying only childhood isn’t the full lifespan focus, measuring lifespan in hours isn’t relevant to development, and a theory that nothing changes after adolescence contradicts abundant evidence of ongoing growth and adaptation throughout adulthood and old age.