Final answer:
Iodine is crucial for the production of thyroid hormones, specifically thyroxine (T4) and triiodothyronine (T3), which are necessary for vital physiological functions.
Step-by-step explanation:
Iodine is essential for the synthesis of thyroid hormones. The two primary thyroid hormones are thyroxine (T4) and triiodothyronine (T3), which are synthesized from tyrosine in the presence of iodine. Iodine uptake by the thyroid gland is facilitated by an active transport mechanism, and its conversion to active iodine within the gland requires the enzyme thyroperoxidase along with hydrogen peroxide. These hormones are critical for various physiological functions, including cellular oxidation, growth, and central nervous system activity. Without sufficient iodine in the diet, there can be a risk of developing a goiter, which is an enlargement of the thyroid gland. Consequently, the answer to the question is b) Thyroid hormones.