The 20% of Adolescents in the United States Who Are

The 20% of adolescents in the United States who are "only" children have been found by research to experience which of the following because of being only children?

A) loneliness and a tendency to isolate themselves
B) fairly high self-esteem and achievement motivation
C) serious jealousy of children from large families
D) high-risk behaviors in at least three areas of their lives