What research finding about family-based prevention programs is false?

What research finding about family-based prevention programs is false?
 
  a. Parental education programs that improved parenting skills showed significant results in educational success, delinquency, and cognitive development of juveniles.
  b. Results indicated that early family/parent training is an effective intervention for reducing antisocial behavior and delinquency.
  c. Multi-component programs produced larger effects that program duration and intensity.
  d. These programs produced improved school readiness and school performance for the children.