A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of:________.a. the influence of environment on development.b. heterochrony.c. a change in a developmental gene or its regulation that altered the spatial organization of body parts.d. gene duplication.

The given type of change is illustrative of a change in a developmental gene or its regulation that altered the spatial organization of body parts

Hox genes encode conserved homeodomain transcription factors that possess significant developmental power in shaping animal morphology
Hox genes are also expressed in the nervous system of Drosophila and have a wide array of functions in the development of the peripheral and central nervous system (CNS)
In the peripheral nervous system of Drosophila, Hox genes are required for sensory organ development as well as for proper formation of neuromuscular networks
During embryogenesis of the CNS, Hox genes are involved in the establishment of regional neuronal identity, in fate specification in different segments, in regionalized programmed cell death of post mitotic neurons, and in the control of neural proliferation
During post-embryonic development of the CNS, Hox genes are involved in limiting the proliferative potential of neural
Hox genes and their cofactors are also subject to cross-regulatory interactions in neural patterning