Which of the following could be evidence that an organism's growth is influenced by the organism's genes?

(Hint: Identical twins have identical genes. Non-identical twins have about half the same genes.)

Identical twins are more likely to be about the same height than non-identical twins.
Identical twins often have slightly different weights at birth.
A dog breed can be made smaller by breeding together only the smallest dogs.
Children are likely to have friends who are about the same height.