Allen test is used for -

Ans. is 'b' i.e., Radial or ulnar artery patency "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