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: Medicine
[{'content': 'All of the following components or qualities of stored whole blood tend to decrease over time except: \nSelect and explain. \nA. Red blood cell viability, B. Potassium concentration, C. PH, D. Platelet activity', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]