Question

the final and longest period of prenatal development is the period of the: embryo. zygote. placenta. fetus.

Explanation:

Prenatal development has three main stages. The zygote stage is the initial stage after fertilization. The embryonic stage follows and is a period of major organ - formation. The fetal stage is the final and longest stage, lasting from the 9th week until birth, during which the fetus grows and matures.

Answer:

D. fetus