While Having One or Two Siblings Is Positively Related to Better

While having one or two siblings is positively related to better social skills,
Additional siblings

A) increase the development of social skills significantly.
B) do not make any noticeable difference in the development of social skills.
C) lead to a decrease in social skills.
D) lead to increased social skills within the family, but made no difference outside the family.
E) lead to increased social skills within the family, but decreased social skills outside the family.