This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Body composition and Acid base Balance, Subject name: Pediatrics
[{'content': 'What is the name of this test to be done before drawing an aerial 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: Allen's test: to assess the aerial blood supply of the hand A - Both radial & ulnar aery are occluded; B - Ulnar aery kept occluded, Radial aery released Water hammer test- to detect water hammer pulse in aoic regurgitation Trendelenburg test- to detect weakness of hip abductors", 'role': 'assistant'}]