<prompt> Which plasma protein is necessary for adhesion of platelets to subendothelial fibres?Glycoprotein IIbVon Willebrand factorPlatelet factor 3Factor X  <response>: b. Von Willebrand factorRef: Nelsons 20e p 2386-2390, Ghai 8e p 349Von Willebrand factor present in plasma and expressed on endothelium after tissue injury is necessary for platelet adhesion with the help of Gp IbIX on platelets. 