Brad Has Been Diagnosed with Oppositional Defiant Disorder ODD)

Brad has been diagnosed with oppositional defiant disorder ODD) . The disorder began around age 12 and is characterized by disobedient and hostile behavior toward authority figures. What aspect of this case is unusual?

A) Nothing about this case is unusual.
B) It is unusual for children with ODD to be boys.
C) It is unusual for the onset of ODD to occur at age 12.
D) It is unusual for children with ODD to be hostile toward authority figures.