The Idea That Genes Play a Role in Maturation and Eventual

The idea that genes play a role in maturation and eventual stature is supported by evidence that

A) with age, fraternal twins becoming increasingly similar in height.
B) Africans proceed through puberty faster than do Europeans when they share an equivalent quality of life.
C) identical female twins rarely reach menarche on exactly the same day.
D) adopted siblings are similar to each other in body size and shape.