Some Correlational Studies Have Found That People Who Are Chronically

Multiple Choice

Some correlational studies have found that people who are chronically depressed are more likely than non-depressed people to develop cancer. Which of the following can be derived from the study?

A) Chronic depression causes cancer.
B) Early, undetected cancer causes depression.
C) Depressed people tend to smoke, causing cancer.
D) Chronic depression and cancer are related to one another.