The correct option is A vasopressin
∙ Kidney helps in excreting the waste product out of the body through urine.
∙ An antidiuretic hormone called vasopressin helps the kidney to reabsorb the water back into the body.
∙ It helps in maintaining the concentration of urine.
∙ Diabetes insipidus is a rare disorder which is caused due to lack of vasopressin.
∙ The person suffering from this disorder pass an abnormally large volume of dilute urine out of the body.