It Has Been Reported That Average Scores on National Exams,such

Multiple Choice

It has been reported that average scores on national exams,such as the Scholastic Aptitude Test (SAT) ,have declined in recent years.Researchers interested in exploring this intensively interview students who have just taken the exam,those who took it last year,and those who took it five years ago.This method is:

A) longitudinal.
B) experimental.
C) correlational.
D) cross-sectional.