This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
Which of the following is a cause of extravascular hemolysis- 
Select and explain. 
A. Falciparum malaria, B. Sickle cell disease, C. Mismatched blood transfusion, D. Microthrombi in circulation
B: Sickle cell disease
Answer: B: Sickle cell disease 
Explanation: Extravascular hemolysis is generally caused by alterations that render the red cells less deformable. Reduced deformability makes the passage difficult leading to red cell sequestration and phagocytosis by macrophages located within splenic cords.This occurs in sickle cell anemia. Intravascular hemolysis caused by intracellular parasites like plasmodium falciparum. Mechanical injury also causes intravascular hemolysis. It can be occured by thrombotic narrowing of microcirculation. Mismatched blood transfusion also causes intravascular hemolysis. Reference : Robbins and Cotran Pathologic basis of disease.South Asia Edition volume 1.page no. 631