Pathology A critical factor in the regulation of craniofacial development A Sonic hedgehog (SHH) B Fibroblast Growth factor (FGFz) C Wingless Drosophila melanogaster segment — Polarity gene (Wnt) D Bone Morphogenic Protein (BMP) 💡 Explanation A critical factor in the regulation of craniofacial development ✓ Correct Answer: A. Sonic hedgehog (SHH)