32. A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of fartherback helped make possible the evolution of the tetrapod limb. This type of change is illustrative of
(A) the influence of environment on development.
(B) paedomorphosis.
(C) a change in a developmental gene or in its regulation that altered the spatial organization of body parts.
(D) heterochrony.
(E) gene duplication.