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
[{'content': "Activity of factor VIII procoagulant is deficient in: \nSelect and explain. \nA. Haemophilia, B. Von Willibrand's disease, C. ITP, D. Sickle cell anemia", 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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', 'role': 'assistant'}]