Concept:The placenta is the main organ where exchange of materials between mother and foetus takes place.
Explanation:During pregnancy, the embryo attaches to the wall of the uterus through the placenta.
The placenta develops special finger-like structures called villi that increase the surface area for exchange.
Food nutrients, oxygen, and water diffuse from the mother’s blood across the placenta into the foetus’s blood.
At the same time, waste products like carbon dioxide and urea move from the foetus back into the mother’s blood.
The placenta acts as the lifeline between the mother and the growing foetus.
The umbilical cord mainly connects the foetus to the placenta and contains blood vessels.
The amnion is the fluid-filled sac around the foetus, while the chorion is an outer membrane.
Therefore, the organ that actually supplies food from the mother to the foetus is the placenta.
Answer:D. Placenta