This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Arterial Disorders, Subject name: Surgery
Allens test detects insufficiency of which artery - 
Select and explain. 
A. Radial artery, B. Umbilical artery, C. Popliteal artery, D. Aorta
A: Radial artery
Answer: A: Radial artery 
Explanation: Ans. is 'a' i.e., Radial artery "Allen test the adequacy of blood supply to the hand from radial and ulnar arteries and the arcade between them".TestTechniqueSignificanceAllens testElevate the hand and apply digital pressure on the radial and ulnar arteries to occlude them.Ask the patient to make a fist several times. The tips of the finger should go pale. Release each artery in turn and observe the return of colourTests the adequacy of the blood supply to the hand from the radial and ulnar arteries and the arcade between them