Here is the answer...hope it helps:)
I believe this is a bit of a trick question, while you are right about both B and D, they both preexist they just develop into other structures. I believe the correct answer is A since the nerve cord is hollow not solid.
Answer:
glucagon
Explanation:
Glucagon is a hormone that is involved in controlling blood sugar (glucose) levels. It is produced by the alpha cells, found in the islets of Langerhans, in the pancreas, from where it is released into the bloodstream.
