Concept:Rh incompatibility between an Rh-negative mother and an Rh-positive foetus can cause harmful immune reactions.
Explanation:During a first pregnancy with an Rh-positive baby, the Rh-negative mother may become sensitised and produce anti-Rh antibodies.
These antibodies remain in her blood.
In a second Rh-positive pregnancy, the antibodies cross the placenta.
They enter the foetal bloodstream and cause the foetal red blood cells to clump or agglutinate.
This destruction of red blood cells leads to severe anaemia and may cause stillbirth.
Answer:C. the blood of the foetus might clump