Anticoagulant  used for osmotic fragility test: (A) EDTA, (B) 3.2 % Trisodium citrate, (C) Heparin, (D) Warfarin
Answer is C. Heparin - osmotic fragility test.
EDTA - Blood cell counts.
3.2% trisodium citrate  - ESR, platelet studies.