Concept:In children, under-secretion of
thyroxine causes cretinism, a form of hypothyroidism that impairs growth and development.
Explanation:The thyroid gland secretes
thyroxine, which is vital for normal physical growth and brain development in children.
When too little
thyroxine is produced during childhood, the child may experience stunted growth, mental retardation, and delayed development.
This condition is known as cretinism.
It is different from goitre, which is simply an enlarged thyroid gland, and from gigantism, which is caused by excess growth hormone.
Answer:D. cretinism