This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Embryology, Subject name: Anatomy
[{'content': 'Hypoblast forms: \nSelect and explain. \nA. Notochord, B. Apical ligament of atlas, C. Endoderm, D. Prochordal plate', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. D Prochordal plateRef: Netter's Clinical Anatomy, 3rd ed. pg. 39* Hypoblast and epiblast are 2 germ layers in the second week of embryonic development.* The hypoblast gives rise to prochordal plate which is the future site of mouth and forms the cranio-caudal axis.* Notochord is formed by epiblast cells.* Epiblast is also the source of all three germ layers.* First germ layer to be formed is the endoderm. Q* Remnants of notochord are nucleus pulposus and apical ligament of atlas.", 'role': 'assistant'}]