This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Embryo proper is derived from 
Select and explain. 
A. Cytotrophoblast, B. Inner cell mass, C. Syncytotrophoblast, D. Amniogenic cells
B: Inner cell mass
Answer: B: Inner cell mass 
Explanation: Outer cell mass forms trophoblast.
Inner cell mass forms embryoblast.