This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharyngeal Arches, Subject name: Anatomy
Pouches are lined by which germ layer? 
Select and explain. 
A. Endoderm, B. Ectoderm, C. Mesoderm, D. Both Mesoderm and Ectoderm
A: Endoderm
Answer: A: Endoderm 
Explanation: Pouches inside are lined by Endoderm Clefts outside are lined by Ectoderm