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."
The reasoning in the psychologist's argument is most vulnerable to criticism on the grounds that it

A) Presumes, without providing justification, that university students have a higher rate of depression than do overnight workers.
B) Fails to consider the possibility that poor eating habits are an effect, not a cause, of depression.
C) Fails to give a definition for what constitutes depression.
D) Presumes that all depression is caused by the same thing in all people.
E) Presumes that overnight workers are less healthy than those who work other shifts.