What Is the Difference Between the Depressive Episodes Associated with Bipolar

What is the difference between the depressive episodes associated with bipolar II disorder from those associated with bipolar I disorder?

A) They are less frequent than those associated with bipolar I disorder
B) They are lengthier than those associated with bipolar I disorder
C) They are less severe that those episodes associated with bipolar I disorder
D) They are less disabling that those associated with bipolar I disorder