During the early development of a human embryo, the eventually forms the

During the early development of a human embryo, the epiblast eventually forms the ectodermal, mesodermal, and endodermal tissues.
Epiblast is a part of the inner mass cell whose primary function is to create these three types of tissues for the human embryo. Ectoderm is the most exterior layer of germ, mesoderm is the middle layer, and endoderm is the most proximal layer.

C- a hypothesis or d- an observation