Which of the Following Research Studies Would Be Considered a Cohort

Multiple Choice

Which of the following research studies would be considered a cohort study?

A) interviewing the same employees of a bank every month for two years
B) conducting a one-time survey in a college lecture hall
C) surveying teenagers now, then 20 year olds in a decade, then 30 year olds a decade after that
D) interviewing police officers now regarding their educational background, and then interviewing police officers again in 2 years
E) examining a selection of textbooks to analyze how conflict theory is presented