A Key Difference Between Major Depressive Disorder and Bipolar Disorder

A key difference between major depressive disorder and bipolar disorder is that:

A) bipolar disorder includes manic symptoms,whereas major depressive disorder does not.
B) major depressive disorder includes manic symptoms,whereas bipolar disorder does not.
C) bipolar disorder includes depressive symptoms,whereas major depressive disorder does not.
D) major depressive disorder includes depressive symptoms,whereas bipolar disorder does not.