Answer:
d. ectoderm
Explanation: A particular locale of this layer, the neuroectoderm, turns into a section that folds in and turns into the neural cylinder underneath the dorsal surface of the fetus. The front finish of the neural cylinder forms into the cerebrum, and the back area turns into the spinal line
endoderm: essential germ layer that proceeds to frame the gastrointestinal tract, liver, pancreas, and lungs
while, ectoderm: essential germ layer that forms into the focal and fringe sensory systems, tactile organs, epidermis, hair, and nails