After birth, a direct Coombs test is performed on the umbilical cord blood of a neonate with Rh-positive blood born to a mother with Rh-negative blood. The nurse explains to the client that this test...

After birth, a direct Coombs test is performed on the umbilical cord blood of a neonate with Rh-positive blood born to a mother with Rh-negative blood. The nurse explains to the client that this test is done to detect which of the following?

1. Degree of anemia in the neonate.

2. Electrolyte imbalances in the neonate.

3. Antibodies coating the neonate's red blood cells.

4. Antigens coating the neonate's red blood cells.