Best assay for deficiency of von Willebamd factor is:
Answer is C (BT + APTT + vWF-ristocetin factor assay) Estimation of BT, APTT and VWF-Ristocetin factor assay would provide the maximal information to aid a diagnosis of VWF disease (amongst the options provided)
Bleeding time
BT + APTT
BT + APTT + vWF-ristocetin factor assay
PT