<prompt> Which plasma protein is necessary for adhesion of platelets to subendothelialfibres?Glycoprotein IIbVon Willebrand factorPlatelet factor 3Factor X  <response>: Ans. b Von Willebrand factorRef: Robbins 9thpg 661Von Willebrand factor is necessary for adhesion of platelets to subendothelial fibres. 