Which Statement Best Explains Why a CNS Stimulant Helps a Patient

Which statement best explains why a CNS stimulant helps a patient with attention-deficit hyperactivity disorder (ADHD) ?

A) Neurotransmitters are blocked,limiting the effects they can produce within the PNS.
B) Activation of certain areas of the brain causes increased attention and ability to focus.
C) Neurotransmitter levels are reduced,which produces a calming effect within the CNS.
D) Certain areas of the brain are deactivated,resulting in a calming effect.