A 23-year-old G2 P1 woman has noted minimal fetal movement in the second trimester. An ultrasound scan at 19 weeks shows hydrops fetalis. A girl infant is born at 32 weeks gestation and is markedly icteric. The microscopic appearance of the placenta is shown here. Laboratory studies show the baby has a Hct of 18%, and an exchange transfusion is performed. Her first pregnancy was uncomplicated and resulted in the birth of a normal girl at term. Which of the following immunologic mechanisms is most likely to produce these findings? <image 1> 
['Anti-receptor antibody', 'Immune complex formation', 'Complement mediated cell destruction', 'Delayed type hypersensitivity', 'Loss of self tolerance']