All of the Following Present Evidence That ADHD Has a Biological

All of the following present evidence that ADHD has a biological component EXCEPT

A) the behavioral pattern begins very early and has a very strong physical component.
B) biological treatment, i.e. stimulant medication, is very often effective.
C) if one identical twin is diagnosed as hyperactive, the other is likely to have the same diagnosis.
D) teachers often report that children first model ADHD behaviors they witness in other children prior to diagnosis.
E) brain imaging scans show subtle differences in brain structure and function between individuals with ADHD and those without.