This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Activity of factor VIII procoagulant is deficient in: 
Select and explain. 
A. Haemophilia, B. Von Willibrand's disease, C. ITP, D. Sickle cell anemia
A: Haemophilia
Answer: A: Haemophilia 
Explanation: A i.e. HemophiliaHemophilia A is a disorder of coagulation occurs due to deficiency or reduced activity of factor VIII.FeaturesHemophilia A (Classical hemophilia)Hemophilia B (Christmas disease)DefectDeficiency of coagulant subunit of factor VIII i.e. VIIICfactor VIII=VIIIC + VWFDeficiency of factor IXQPathway ofcoagulation affectedInstrinsic pathwayIntrinsic pathway