When Comparing Firstborn to Later-Born Children,what Must Researchers Remember and Consider

Multiple Choice

When comparing firstborn to later-born children,what must researchers remember and consider?

A) Effects of birth order are more significant for girls than for boys.
B) ​Some parents give their children more attention than others do.
C) ​Children in one-child families differ from those in larger families.
D) ​Child-rearing practices are different today from those of long ago.