According to the Textbook, One Limitation of Studies of Youth

According to the textbook, one limitation of studies of youth in self-care is that:

A) self-care youths are a difficult sample to recruit.
B) researchers typically lump together all children who take care of themselves after school.
C) parents of self-care youths rarely agree to allow their teenagers to participate in research studies.
D) self-care youths are more likely than non-self-care youth to drop out of research studies.