The correct option is C Tyrosine
The thyroid gland has thyroid follicles composed of follicular cells which synthesise two hormones, tetraiodothyronine or thyroxine (T4) and triiodothyronine (T3). The follicular cells add the amino acid tyrosine to a glycoprotein called thyroglobulin. The thyroglobulin here is actually the precursor for these thyroid hormones.