Answer: A. embryo
Step-by-step explanation:
The embryo is the early stage of development of the precursor of new life. It is a multicellular diploid organism. The development of embryo is the characteristic feature of eukaryotic organisms. It develops after the process of fertilization in sexual mode of reproduction. The cells of the embryo divide and differentiate to take the form of distinct of organs. These organs performs specialized functions in the body of the organism.