In human development, what is the site of early blood cell formation for the fetus?

A) umbilical cord
B) placenta
C) amniotic fluid
D) yolk sac
E) allantois

Blood Cell Formation

The process of creating new blood cells, also known as hematopoiesis, occurring mainly in the bone marrow.

Yolk Sac

One of the extraembryonic membranes that, in shelled vertebrates, contains yolk for the nourishment of the embryo, and in placental mammals is the first site for blood cell formation.