Which antigens are commonly associated with alloimmunization and fetal hydrops?

The most commonly associated antigens with alloimmunization and fetal hydrops are the c, D, E, K, and e antigens, which are part of the Rh and Kell blood group systems. Alloimmunization occurs when an individual is exposed to foreign antigens, typically through blood transfusions or during pregnancy. In cases of Rh incompatibility, the D antigen is particularly significant as it can lead to hemolytic disease of the fetus and newborn (HDFN), where maternal antibodies attack fetal red blood cells. The presence of other antigens such as c, E, and K can also contribute to similar situations if sensitization occurs.

Fetal hydrops, characterized by an abnormal accumulation of fluid in fetal compartments, can arise from severe anemia caused by alloimmunization. When maternal antibodies target these significant blood group antigens, it can lead to the destruction of fetal red blood cells, resulting in anemia and ultimately fetal hydrops. Therefore, the association of these specific antigens with alloimmunization makes choice A the correct answer to this question.