The following structure represents all the 3 components of the embryonic disc-
A i.e. Tympanic membraneTympanic membrane derived from first pharyngeal membrane (which seperates 1st pharyngeal groove from 1st pharyngeal pouch) represents all three layers of embryonic disco. It develops from three sources. 1) External very thin skin is derived from ectoderm of 1st pharyngeal groove; 2) Medoderm of 1st & 2hd pharyngeal arches; 3) Internal lining is derived from endoderm of tubotympanic recess, (a derivative of 1st pharyngeal pouch).
Tympanic membrane
Retina
Meninges
None of the above