Which of the following methods involves studying development over time?

A) A longitudinal study
B) An experiment
C) A cross-sectional study
D) A correlational study

Longitudinal Study

Research that follows the same subjects over a period of time, observing changes or development in those subjects.

Development

The process of change or growth that occurs in organisms over time, often referring to physical, cognitive, or emotional maturation.

Experiment

A method of scientific investigation that seeks to discover cause-and-effect relationships by introducing independent variables and observing their effects on dependent variables.