Psychologist: "A Study of College Students Revealed That Those Students

Psychologist: "A study of college students revealed that those students suffering from depression are more likely to eat junk food as opposed to healthier snacks. Another recent study proved that workers who work overnight shifts have higher rates of depression than those who work day or evening shifts. Thus it is very likely that poor eating habits are a cause of depression, as overnight workers also often have a poor diet due to their inability to keep a consistent schedule and easily share meals with others."
If added to the original passage, which of the following would most strengthen the psychologist's argument?

A) In another study, depression sufferers who tracked their eating habits found that when they ate more nutritious foods their symptoms of depression decreased.
B) People with depression often suffer from other illnesses as well.
C) Another study showed that students with depression were more likely to have lower grades and lower participation levels in student activities.
D) In another study, overnight workers who exercised at least three times a week had lower rates of depression than those who did not.
E) Depression is often under diagnosed and the rates of depression in the general population is probably much greater than is currently known.