Hi lovely,
The answer you're looking for would be Biosphere.
The appropriate response is A. Gastrulation is a stage ahead of schedule in the embryonic improvement of most creatures amid which the single-layered blastula is rearranged into a trilaminate (three-layered) structure known as the gastrula. These three germ layers are known as the ectoderm, mesoderm, and endoderm.
