Albert Is Interested in How Thinking Changes in Adolescence and Early

Albert is interested in how thinking changes in adolescence and early adulthood. She indentifies a group of people who are 18 years old, a second group who are 22 years old, and a third group who are 26 years old. She asks participants in all three groups to answer some questions testing their moral reasoning skills. Her research study is best considered an example of:

A) a longitudinal study
B) a cross-sectional study
C) a sequential-cohort study
D) an age-cohort experiment