This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Which one of the following is used for preservation of blood for transfusions 
Select and explain. 
A. Heparin, B. Citrate phosphate dextrose, C. Thrombin, D. None of the above
B: Citrate phosphate dextrose
Answer: B: Citrate phosphate dextrose 
Explanation: Whole Blood Anticoagulant used Maximum storage ACD/CPD/CP2D 21 days CPDA-1 (Citrate phosphate dextrose Adenine) 35 days SAGM(Saline, Adenine, glucose, mannitol) 42 days Actions of ingredients of anticoagulant solution Glucose - ATP generation by glycolysis Adenine - Synthesis of ATP. Increases shelf life of RBC to 42 days Citrate - Prevents coagulation by chelating calcium Sodium diphosphate - Maintain optimum pH Ref: Sabiston 20th edition Pgno :588