Researchers at the National Cancer Institute Queried Men and Women

Multiple Choice

Researchers at the National Cancer Institute queried men and women aged 50 and older about their diets, then followed participants for five years to record all diagnoses of head and neck cancer, which is the sixth-leading cause of cancer-related death worldwide. This is an example of

A) A retrospective, case-control observational study.
B) A prospective, cohort observational study.
C) A simple random survey.
D) A multistage sample survey.