Which of the Following Statements Is True About the Epigenetic

Which of the following statements is true about the epigenetic interplay between maternal smoking and attention-deficit hyperactivity disorder (ADHD) ?

A) By itself, the DD genotype was related to impulsivity and oppositional behavior.
B) Children of mothers who smoked during pregnancy scored lower in overactivity than children of nonsmoking mothers.
C) Five-year-olds with both prenatal nicotine exposure and the DD genotype obtained substantially higher impulsivity scores than all other groups.
D) Five-year-olds with both prenatal nicotine exposure and the DD genotype obtained lower oppositional behavior scores than all other groups.