Answer:
cross-sectional study.
Step-by-step explanation:
A cross-sectional study consists of a research design that compares various individuals of different ages or levels of development at a specific point in time. For example, if you compare 4-year-old kids with 9-year-old kids. This kind of study is not appropriate to measure changes as time passes. In this case, a longitudinal study would be the right one to implement.