Epidemiological studies:

A) can establish that a risk factor causes a disorder.
B) overcome almost all of the limitations of correlational studies.
C) are generally unaffected by the problem of the third variable.
D) provide valuable information on the prevalence, incidence, and risk factors for disorders.

Epidemiological studies provide valuable information on the prevalence, incidence, and risk factors for disorders. While they can suggest a possible causal relationship, they cannot establish definitively that a risk factor causes a disorder. Additionally, epidemiological studies are still susceptible to the problem of the third variable and other limitations of correlational research.