The correct option is A Pancreas
The antagonistic function of insulin and glucagon hormones of pancreas maintains blood glucose level. Insulin lowers the blood glucose level by stimulating the uptake of glucose by cells while glucagon stimulates the breakdown of glycogen into glucose to increase the blood sugar level. Thyroid hormones regulate the metabolic rate while anterior pituitary control hormonal secretion of other glands. Posterior pituitary releases vasopressin and oxytocin. The hypothalamus regulates pituitary gland by regulatory hormones. Thus, the correct answer is option