The National Institute of Mental Health is conducting a study of memory and response time in relation to timed tasks in groups of 50- to 75-year-old adults. The researchers are bringing in these age groups at once in order to compare the differences. This is a(n) study.

A cross-sectional

Explanation:A cross-sectional study is the one that focuses on studying a particular population at one specific point in time.

The researcher chooses their variable of interest and the one specific group of which h(she) will use to study this variable. They are commonly used in developmental psychology and other areas. This study is more observational and descriptive but it is not causal which means it doesn't aim to identify the cause of what is being observed it only determines what characteristics are there in that population.

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