Dr. Gillian Davies, a clinical psychiatrist, is treating Samantha, a young woman in her twenties who seemed to have developed multiple selves. One of Samantha's alters claims to be a reclusive artist, while another alter is a flamboyant dancer. Dr. Davies is most likely treating Samantha for _____.
a. Dissociative Identity Disorder
b. Bipolar Disorder
c. Schizophrenia
d. Borderline Personality Disorder