Considering the Underlying Causes of Bipolar Disorder and Major Depressive

Considering the underlying causes of bipolar disorder and major depressive disorder,we could conclude that biological factors are

A) more important in bipolar disorder than in major depressive disorder.
B) more important in major depressive disorder than in bipolar disorder.
C) equally important in both major depressive disorder and bipolar disorder.
D) of minor importance in both major depressive disorder and bipolar disorder.