Which of the following is not considered a criterion that suggests the presence of a psychological disorder under the category of “maladaptiveness”?
a. personal unhappiness
b. impaired functioning
c. long periods of discomfort
d. disruptive behavior

The thing which isn't considered to be a criterion that suggests the presence of a psychological disorder under the category of maladaptivness would be c - long periods of discomfort. It's true that people who are personally unhappy, have impaired functioning and exhibit disruptive behavior will also be ones who woud fall under the category of maladaptiveness.