Correct Answer - C
Thyroxine `(C_(15) H_(14) I_(4) NO_(4))` is an iodine-containing amino acid hormone produced by the thyroid gland. The pure form is a white crystalline substance `(mp 236^(@)C)`. It is used in cases of thyroid deficiency. It stimulates the consumption of oxygen and thus, the metabolism of cells or tissues in the body.
The thyroidal hormones such as thyroxin and triiodothyronine affect the general metabolism, regardless of the nature of their specific activity is for this reason why thyroid gland is known as pane setter of the endocrine system.
