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
Pharyngeal arches are rod like thickning of: 
Select and explain. 
A. Endoderm., B. Ectoderm., C. Mesoderm., D. All of the above.
C: Mesoderm.
Answer: C: Mesoderm. 
Explanation: None