A mother brings her four-year-old son in for evaluation because he 'does not get along with his step-siblings.' The mother reports that her son refuses to play a game with his step-siblings unless they play by his rules. According to cognitive development theory, the explanation for the child’s behavior is that he is in the:

Correct Answer: C

Rationale: At age 4, preoperational stage (C) per Piaget includes egocentrism, limiting perspective-taking, explaining the behavior. Industry (A) is later, preconventional (B) is Kohlberg’s moral stage, and concrete operations (D) starts at 7.

Correct Answer: C

Rationale: Nail biting (C) is a disorder defined by repetitive nail biting or thumb sucking, often a nervous habit. Temper tantrums (A) involve outbursts, delinquency (B) law-breaking, and aggressiveness (D) hostility, none of which match the description.

Correct Answer: D

Rationale: Enuresis (bedwetting) management includes psychotherapy (A) for emotional factors, medication (B) like desmopressin, and behavioral therapy (C) like alarms; all (D) are valid per clinical guidelines.

Correct Answer: B

Rationale: Conduct disorder (B) includes persistent stealing as a rule-violating behavior, per DSM-5. Anxiety (A), depression (C), and PTSD (D) don’t typically feature theft.

Correct Answer: C

Rationale: Persistent sadness (C) is a major symptom of childhood depression, per DSM-5. Hyperactivity (A) is ADHD, elevated mood (B) contradicts, and none (D) is incorrect.