Final answer:
When a sensitized Rh-negative mother carries an Rh-positive fetus, her anti-Rh antibodies can attack the fetus's red blood cells, potentially causing hemolytic disease of the newborn (HDN), a serious condition that may be fatal to the fetus.
Step-by-step explanation:
If an Rh-negative mother has been sensitized and is carrying an Rh-positive baby, her immune system can produce anti-Rh antibodies. If exposure to the Rh antigen has occurred in a previous pregnancy, this subsequent exposure can result in a dangerous condition known as hemolytic disease of the newborn (HDN) or erythroblastosis fetalis, where maternal anti-Rh antibodies cross the placenta and attack the fetal red blood cells, potentially leading to severe anemia or death of the fetus. Therefore, the answer to what happens if a sensitized Rh-negative mother carries another Rh-positive baby is: a) Antibodies try to kill the baby (bb).