Hint: he spleen is an organ which is found in most vertebrates. It is located beneath the left diaphragm and is similar in structure to lymph nodes. The primary function of the spleen is the filtering of blood.
The spleen is made up of three different regions- the red pulp, the white pulp and the marginal zone. The red pulp is made up of different blood cells like platelets, red blood cells, granulocytes and also monocytes. It carries out the infiltration of red blood cells. The white pulp comprises T lymphocytes, macrophages and B lymphocytes and helps in defense against foreign particles. The marginal zone consists mostly of antigen presenting cells like dendritic cells and macrophages. Megaly of spleen refers to the enlargement of spleen, this enlargement causes the release of a lytic substance known as lysolecithin that causes destruction of the red blood cell , leading to hemolytic anemia in most individuals. Megaly of spleen can be caused by various health conditions few of which include- malaria, leukemia, heart failure, cirrhosis or viral, bacterial and parasitic infections.
Hence, the correct answer is option (B)
Note: The diagnosis of megaly of spleen is done mostly by abdominal CT. treatment involves splenectomy which is the removal of the spleen, but individuals who do not have spleen are at increased risk of infections. So it can also be treated by giving the affected individuals prophylactic antibiotics.