The correct option is D A- iv, B-iii, C- ii, D-i
The hormone melatonin is released by the pineal gland. It is responsible for our diurnal rhythm, e.g. the sleep-wake cycle.
Hypothyroidism, or a deficiency of the thyroid hormones, during pregnancy causes a defective development and maturation of the growing baby leading to its stunted growth. This condition is called cretinism.
Due to Grave's disease, cancer of the thyroid gland or the development of nodules in the thyroid gland, the rate of synthesis and secretion of the thyroid hormones is increased to abnormally high levels leading to a condition called hyperthyroidism, which causes an abnormal increase in the basal metabolic rate of the body.
Goitre is a swelling of the thyroid gland, which may be caused by dietary iodine deficiency, hypothyroidism, or hyperthyroidism.