Agroup of preschool-age children are enrolled in a study that plans to follow them over time in order to assess behaviors and other characteristics that may predict later development of schizophrenia. this is an example of a(n) design.

Longitudinal

Explanation:

A longitudinal study is a type of observational study that investigates the same group of people repeatedly over a period of years, sometimes decades or even centuries, in scientific research that requires the handling of statistical data on several consecutive generations of parents and descendants. Longitudinal studies employ continuous or repeated measures to follow particular individuals over prolonged periods of time.

They are generally observational in nature, with quantitative and/or qualitative data being collected on any combination of exposures and outcomes, without any external influenced being applied.

The benefit of a longitudinal study is that researchers are able to detect developments or changes in the characteristics of the target population at both the group and the individual level. The key here is that longitudinal studies extend beyond a single moment in time. As a result, they can establish sequences of events.

Hereis an example of a longitudinal study:

In this example we face to the source of most of the knowledge obtained about heart diseases, the Framingham Heart Study, which began in 1948 with 5,209 adult subjects from Framingham, Massachusetts. The study has yielded most of what is known about the effects of diet, exercise, and common medications such as aspirin on heart disease. The Framington Heart Study is now following the third generation of participants which were studied for a certain amount of time through their health care.

b and c would be the answers