Caution in Interpreting the Research on Early and Late Maturation

caution in interpreting the research on early and late maturation is that

A) effects for individuals depend on their particular abilities, experiences, and situations.
B) it is difficult to know if an adolescent is early or late maturing in an age-graded school.
C) most of the research has been conducted with boys.
D) much of the research has been conducted retrospectively with adults.