The placenta develops from the outer cells of the

A) teratogens.
B) zygote.
C) fetus.
D) embryo.

Placenta

An organ that develops in the uterus during pregnancy, providing oxygen and nutrients to the growing fetus while removing waste products from the fetus's blood.

Zygote

The fertilized egg; it enters a 2-week period of rapid cell division and develops into an embryo.

Outer Cells

Cells located on the exterior or surface layer of a biological entity, often contributing to the protection or interaction with the environment.