Studying Ten Years of College Sociology Classes,Rudy Found That the First

Multiple Choice

Studying ten years of college sociology classes,Rudy found that the first three years each class had a higher average GPA than the following seven.He then concluded that the students were smarter during those early years.What has Rudy done?

A) used verstehen.
B) using content analysis.
C) studying manifest content.
D) committing the ecological fallacy.
E) performing a replication.