Juan Is an 8 Year Old Boy in Third Grade

Juan is an 8 year old boy in third grade. He has been struggling with school since first grade, but this year his teacher is fed up. Even though he is a polite child, she can no longer pass him for simply trying his hardest. Juan is frequently out of his seat, misplaces his work, makes careless errors, and distracts other children. It is likely that Juan has ADHD and wasn't previously diagnosed because:

A) Children aren't usually diagnosed until third grade
B) Children are not diagnosed until the behaviours have been present for seven years
C) Juan is Hispanic
D) Juan is Caucasian