This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bleeding Disorders, Subject name: Pathology
Which of the following is the most common manifestation of hemophilia? 
Select and explain. 
A. Hemoptysis, B. Hemarthrosis, C. Hematemesis, D. Mucosal bleeding
B: Hemarthrosis
Answer: B: Hemarthrosis 
Explanation: Ans. (b) Hemarthrosis(Ref: Robbins 9th ed p 663)In all symptomatic haemophilia cases there is a tendency toward easy bruising and massive hemorrhage after trauma or operative procedures. In addition, "spontaneous" hemorrhages frequently occur in regions of the body that are susceptible to trauma, particularly the joints, where they are known as hemarthroses. Recurrent bleeding into the joints leads to progressive deformities that can be crippling. Petechiae are characteristically absent.