(D) Kwashiorkor

Kwashiorkor is a disease caused by the deficiency of protein in the diet. It is a form of malnutrition that particularly affects children in regions where there is a lack of access to an adequate protein source. Symptoms of kwashiorkor include edema (swelling), stunted growth, and changes in skin and hair. The other options listed—Hypokalemia, Dermatosis, and Goitre—are not specifically caused by a deficiency of protein. Hypokalemia is a low potassium level, dermatosis refers to various skin disorders, and goitre is often associated with iodine deficiency leading to thyroid gland enlargement.

(B) Spleen

The organ primarily affected by malaria is the spleen. Malaria is a parasitic infection caused by Plasmodium parasites that are transmitted through the bites of infected mosquitoes. The parasites multiply in the liver and then infect red blood cells, leading to symptoms such as fever, chills, and an enlarged spleen. The spleen plays a crucial role in the immune response against malaria, but the infection can cause it to enlarge as it filters out infected red blood cells from the circulation. If left untreated, severe cases of malaria can lead to complications, including damage to the spleen and other organs.