<prompt> During a laboratory exercise on coagulation testing, a 23-year-old medical student is found to have a prolonged bleeding time. She has had a long history of easy bleeding, with frequent bleeding of the gums, epistaxis, cutaneous bleeding, and menorrhagia. Fuher testing revealed a deficiency of Von Willebrand factor. Which of the following thrombogenic processes involving platelets is most directly impaired?AdhesionConformational change with activation of phospholipid surfaceFormation of fibrinogen bridgesRelease reaction  <response>: Disruption of the endothelium exposes subendothelial von Willebrand factor vWF and collagen, which promote platelet adherence and activation. Deficiency of Von willebrand factor VWF causes platelet adhesion BT and Intrinsic pathway activity aPTT . 