Which hormone aids in water resorption?

It is a vasopressin hormone or antidiuretic hormone (ADH). This is a hormone which is synthesized in neurons in the hypothalamus, and released from the vesicles of the posterior pituitary. Vasopressin is released in response to extracellular fluid hyperosmolality. Its function is to increases the reabsorption of water into the circulation from the filtrate (nephrons of the kidney). Also, it raises arterial blood pressure by constricting arterioles.