<prompt> The following structure represents all the 3 components of the embryonic disc-Tympanic membraneRetinaMeningesNone of the above  <response>: 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. 