Judgments of Normal Weight and Body Composition in Middle-School-Age Children

Judgments of normal weight and body composition in middle-school-age children should be made cautiously because

A) each child is unique and developmental norms are of little use.
B) different ethnic groups and populations seem to differ in developmental rates.
C) existing norms are based on data collected in the 1920s and 1930s and may be inapplicable today.
D) averages and norms for children's height have not been firmly established.