How Is Severity of ADHD Determined,according to the DSM-5

Multiple Choice

How is severity of ADHD determined,according to the DSM-5?

A) based on the number of settings in which symptoms manifest 
B) based on the duration of the disturbance and age of onset
C) based on how many of the three primary symptom classes (hyperactivity, impulsivity, inattention) the child exhibits
D) based on how many symptoms, in excess of the minimum required for diagnosis, the person exhibits and degree of impairment in functioning