Based on Outcome Studies That Have Evaluated the Effectiveness of Light

Multiple Choice

Based on outcome studies that have evaluated the effectiveness of light therapy for seasonal depressions,it appears that

A) many patients with seasonal affective disorders do respond well to light therapy.
B) light therapy is an expensive but useless gimmick.
C) no one knows the correct dosage of light.
D) there is no theory to explain how light therapy could possibly work.