Which of the Following Statements MOST Accurately Describes the Inference

Which of the following statements MOST accurately describes the inference that can be made regarding the possible functional significance of FOXP2 in the evolution of human language?

A) FOXP2 encodes a highly conserved transcription factor that is a "language gene." Changes in the function of this transcription factor in the human lineage were the key event that allowed language to evolve.
B) FOXP2 is a developmental gene with pleiotropic effects. Because this gene is highly conserved among a group organisms that are capable of acoustic communication it must be involved in the evolution of human language.
C) FOXP2 encodes a highly conserved transcription factor. Because songbirds whose FOXP2 gene has been knocked out are less capable of learning new songs, this gene is likely involved in the evolution of human language.
D) FOXP2 is a developmental gene that affects acoustic communication in a range of animal species. Because there were more nonsynonymous than synonymous mutations in the human lineage, changes to the function of this gene in the humans may have contributed to the evolution of language.