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: Pathology
[{'content': 'True regarding estimation of Prothrombin time is: \nSelect and explain. \nA. Immediately refrigerate to preserve factor bility, B. Platelet rich plasma is essential, C. Run the test within 2 hours, D. Activated with Kaolin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: . Run the test within 2 hours', 'role': 'assistant'}]