What differentiates Bipolar I disorder from Bipolar II disorder?

• A. Bipolar I requires at least one manic episode; Bipolar II requires at least one hypomanic episode and one major depressive episode, with no history of a manic episode.
• B. Bipolar I requires at least two depressive episodes; Bipolar II requires no depressive episodes.
• C. Bipolar I and II are distinguished by psychotic features.
• D. Bipolar I is only diagnosed in adults; Bipolar II only in adolescents.

Answer: (A)