If You Think of the Tube-Within-A-Tube Body Plan as a Pipe

Multiple Choice

If you think of the tube-within-a-tube body plan as a pipe with a straw inside,where would you expect to find most of the ectodermal,mesodermal,and endodermal germ layers,respectively?

A) pipe;space between pipe and straw;straw
B) straw;space between pipe and straw;pipe
C) space inside of straw;straw;space between pipe and straw
D) pipe;straw;space inside of straw