The correct option is B Thyroid hormone plays a major role in the differentiation of T lymphocytes.
The deficiency of iodine in our diet results in hypothyroidism and enlargement of the thyroid gland, commonly called goitre.
The thyroid gland secretes a hormone called thyrocalcitonin (TCT) which, along with parathyroid hormone, regulates blood calcium levels.
The thyroid hormone is also involved in maintaining the water and electrolyte balance in the body.
The thymus gland is responsible for the differentiation of T-lymphocytes, which provide cell-mediated immunity.