Answer:
Gastrulation.
Explanation:
Zygote is formed by the fusion of the male and female gamete. The zygote undergoes the process of cleavage to form the different embryonic stages of the offspring.
Gastrulation is the important process of the pre embryonic development. The blastula get multiply and rearranged to form the gastrula. The gsatrulation process includes the formation of three germ layers also known as triploblastic embryo. The three germ layers are ectoderm, endoderm and mesoderm.
Thus, the correct answer is option (C).
