Before blood transfusion in a postpartum hemorrhage (PPH) patient, which test must always be done to prevent hemolytic reaction?

Correct option is C

For safe transfusion, cross-matching is mandatory to prevent acute hemolytic transfusion reaction.
Explanation of options: (a) ✘ Hb helps assess need but not prevent transfusion reaction. (b) ✘ Coagulation profile important in DIC, not transfusion safety. (c) ✔ Correct; cross-match ensures compatibility. (d) ✘ Coombs test detects antibodies, but cross-match is primary safety test.