A 36-Year-Old Male Patient with a Recent Head Injury Complains

A 36-year-old male patient with a recent head injury complains of polyuria. You suspect central diabetes insipidus. How could you confirm the diagnosis?

A) Restrict water intake and treat with insulin and see if urinary volume is decreased.
B) Restrict water intake and treat with angiotensin II and see if urinary volume is decreased.
C) Restrict water intake and treat with arginine vasopressin (AVP) and see if urinary volume declines.
D) Restrict water intake and treat with a loop diuretic to determine if urinary flow rates decrease.
E) Compare urinary production rates following consumption of 3 L of water and 3 L of isotonic saline to determine whether they differ.