I Were to Select a Sample of 30-Year-Olds, Another Sample

Multiple Choice

I were to select a sample of 30-year-olds, another sample of 40-year-olds, and a third sample of 50-year-olds, test or interview them once, and then test or interview them again 10 years later, this would be an example of what kind of research design?

A) cross-sectional
B) sequential
C) longitudinal
D) correlational