Answer:
a. 6 months and present before age 7
Explanation:
Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological, genetic disorder that appears in childhood and often accompanies the individual throughout his or her life. It is characterized by symptoms of inattention, restlessness and impulsiveness. It is sometimes called ADD (Attention Deficit Disorder).
For a student to be diagnosed with ADHD, the Diagnostic and Statistical Manual (DSM-5) suggests that symptomatic behavior must be present for a minimum period of time and must be present before age to justify a classification. This time interval should be between 6 months and present before 7 years.