Ans. (A) Allen test(Ref: Miller's Anesthesia 8th Ed; Page no- 1349-1350)The test performed in the given video is a modification of Allen's test.This test is done mainly prior to radial artery cannulation and drawing blood for ABG analysis.It is useful in identifying adequacy of radial and ulnar collateral blood flow to the hand.Steps:#The patient is first asked to open and close his/her fist to help increase the draining of blood from the hand.#The ulnar and radial arteries are then compressed by the provider's thumbs simultaneously.#The compression is then released from the ulnar artery while maintaining pressure over the radial artery.#This test is repeated in the same hand while releasing the radial artery first and then continuing to compress the ulnar artery.