Deficiency of thyroxine in children causes which leads to mental retardation.

The correct option is A cretinism
Thyroid gland is an endocrine gland responsible for the secretion of thyroxine hormone. Thyroxine is responsible for regulation of carbohydrate, fat and protein metabolism. Deficiency of thyroxine in children causes cretinism which causes retarded physical and mental development. Goitre and myxoedema are also caused because of thyroxine deficiency.