here is the explanation from kaplan:
Neurulation is the process of neural tube formation. The neural plate invaginates and forms a tube. This is
induced through a chemical message from presumptive notochord mesodermal cells, which develop from the
dorsal lip of the blastopore.
i also thought the answer was D, and when i looked on google for more info, i couldnt find much about it...
mannythemanatee, is right it is B.
This is the sort of question that in its simplicity can cause an anxious test taker to make a stupid mistake. As soon as you see neurulation you think ectoderm, but of course that is where it occurs, while it is induced by cells in the dorsal lip of the blastopore.