Scientists enroll 500 healthy adults in a study and collect dietary and other lifestyle
information about the group. After 6 years, the scientists determine that study participants
who ate at least 5 servings of fruits and vegetables daily were less likely to develop high
blood pressure than participants who ate fewer than 5 servings of these foods daily. This study
is an example of a(n) study.
A. prospective
B. nutritive
C. retrospective
D. introspective

The correct option is A: Prospective Study

Explanation:

A prospective study is sometimes referred to as a prospective cohort study. This is usually a study involving a group, in which the participants are enrolled for the study prior to them developing the outcome that is being studied. From the study in the question, the scientist enrolled 500 healthy adults, which means that when he enrolled them, they were healthy and had no issues whatsoever. It was after 6 years that he began to take their blood pressure, which is the outcome of the study.