Julianna is a nine-year-old child diagnosed with attention deficit hyperactivity disorder. her mother was a chain smoker even after julianna was conceived. which of the following factors is chiefly responsible for her condition? a. julianna has one form of a dopamine gene but not the other. b. julianna has abnormal brain growth rate. c. julianna consumed excess amounts of sugar as an infant. d. julianna inherited both forms of a dopamine gene from her mother. e. julianna has one form of a dopamine gene but not the other