This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'University of Wisconsin solution is used in: \nSelect and explain. \nA. Organ preservation, B. Virus isolation, C. Gene therapy, D. All of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: The most commonly used fluid worldwide is the University of Wisconsin solution. It contains lactobionate, raffinose, and hydroxyethyl starch. Lactobionate is impermeable and prevents intracellular swelling; it also lowers the concentration of intracellular calcineurin and free iron, which may be beneficial in reducing reperfusion injury. Hydroxyethyl starch, a synthetic colloid, may help decrease hypothermia-induced cell swelling of endothelial cells and reduce interstitial edema. Another solution that is now being used commonly is histidine-tryptophan-ketoglutarate solution Ref: Schwaz's principle of surgery 9th edition, chapter 11.", 'role': 'assistant'}]