See, haemophilia is a genetic disorder whose inheritance is controlled by a recessive X-linked chromosome . Hemophilia patients have lower blood plasma clotting factor level or impaired activity of the coagulation factors needed for a normal clotting process. Due to this whenever a blood vessel is tampered, coagulation is delayed because the missing coagulation factors prevent fibrin formation, which is necessary to maintain the blood clot.
----answer is net formation by fibrin threads