This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Palatoglossus develops from: 
Select and explain. 
A. Occipital myotomes, B. Lingual swelling of first arch, C. Third arch, D. Mesoderm of sixth arch
D: Mesoderm of sixth arch
Answer: D: Mesoderm of sixth arch 
Explanation: Muscles of tongue develop from occipital myotomes, so the cranial nerve XII (hypoglossal nerve) supplies all intrinsic and three extrinsic muscles. Only palatoglossus is supplied by cranial root of accessory through pharyngeal plexus and is developed from mesoderm of sixth arch.