When crossmatching for a group A D- positive patient experiencing severe hemolysis after receiving IV RhIG to treat ITP, which of the following RBCs should be selected?

  1. group A D-negative
  2. group A D-positive
  3. group O D-positive or D-negative (either is suitable)
  4. group A D-positive or D-negative (either is suitable)
  5. all of the above are suitable

a. group A D-negative