This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
The following structure represents all the 3 components of the embryonic disc 
Select and explain. 
A. Tympanic membrane, B. Retina, C. Meninges, D. None of the above
A: Tympanic membrane
Answer: A: Tympanic membrane 
Explanation: The outer epithelial layer formed by the ectoderm, inner mucosal layer by the endoderm and middle fibrous layer by the mesoderm. Ref: Dhingra 6th edition page no.12