A professor is talking about a movie in which a woman shows three distinct personalities. The topic being discussed in class that day is likely:

A professor is talking about a movie in which a woman shows three distinct personalities. The topic being discussed in class that day is likely: dissociative identity disorder

Explanation:

Dissociative identity disorder or multiple personality disorder is the disorder characterized by the existence of two or more identities or personality states that control the behavior of the individual in an alternating way. In this disorder there is an amnesia consisting of the inability to remember relevant personal information about any of the coexisting identities. Each of the personalities present has a particular pattern of perceiving and interacting with the environment.