True about Von Willebrand's disease is all c.Ic cpt :
Answer is C (Increased platelet aggregation in response to Ristocetin) Willebrand disease is characterized by decreased (impaired) platelet aggregation in response to Ristocetin. Deficiency of Factor VIII is characteristic of hemophilia and not VWF disease. VWF however serves as a carrier for factor VIII c and its deficiency therefore leads to decreased availability of factor VIII c at the site of injury. Decaresed level of factor VIII c in the circulation may therefore be explained by a deficiency of vW factor.
Increased bleeding time
Factor VIII c levels are decreased in circulation.
Increased platelet aggregation in response to Ristocetin
APTT is increased