A severe deficiency of thyroxin results in

Thyroxin is a hormone produced by the thyroid gland, which is located in the neck region. It regulates metabolism, growth, and development in the body. The question is asking what would happen if there is a severe deficiency of thyroxin in the body.

Option A, diabetes mellitus, is not correct because diabetes mellitus is a disease that occurs when the body cannot produce or use insulin properly, and it is not related to the thyroid gland or thyroxin.

Option B, sexual underdevelopment, is also incorrect because although thyroxin plays a role in sexual development, a severe deficiency of thyroxin would not directly cause sexual underdevelopment.

Option D, gigantism, is also incorrect because gigantism is a condition that occurs due to an excess of growth hormone, not a deficiency of thyroxin.

Option C, cretinism, is the correct answer because cretinism is a condition that occurs due to a severe deficiency of thyroxin during fetal development or infancy. It can lead to stunted growth, mental retardation, and other developmental abnormalities.

Therefore, the correct answer to the question is option C, cretinism. It is important to note that a mild deficiency of thyroxin may not cause any noticeable symptoms, but a severe deficiency can have serious consequences.