The odd one out is osteomalacia. The other four options are all forms of malnutrition, while osteomalacia is a bone disease caused by a lack of vitamin D.
Kwashiorkor is a protein-energy malnutrition that occurs in children who are weaned too early and are not given enough protein-rich foods. It is characterized by a swollen belly, thin arms and legs, and a pot-shaped head.
Cretinism is a form of mental retardation caused by a lack of iodine in the diet. It is characterized by a large head, short stature, and a slow mental development.
Marasmus is a form of malnutrition that occurs in children who are not given enough calories. It is characterized by a thin body, loose skin, and a lack of energy.
Goitre is a swelling of the thyroid gland, which is located in the neck. It is caused by a lack of iodine in the diet.