This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid and Electrolyte Treatment of Specific Disorders, Subject name: Pediatrics
[{'content': 'What is the name of this test to be done before drawing an arterial blood gas sample: \nSelect and explain. \nA. Virchow test, B. Water hammer test, C. Allen test, D. Trendelenburg test', 'role': 'user'}, {'content': "Answer: C \nExplanation: c. Allen testA - Both radial & ulnar artery are occluded;B - Ulnar artery kept occluded, Radial artery released; These are steps of Allen's test", 'role': 'assistant'}]