Define the V2 receptor antagonist

A new drug named ANTI-V2R has been developed that is a V2 receptor antagonist.  When ANTI-V2R binds to a V2 receptor, there is no binding of vasopressin to that V2 receptor and there is no activation of G proteins.  ANTI-V2R will help relieve some of the problems for which of the following patients?

  A.  A patient with nephrogenic diabetes insipidus caused by a mutation in the AQP2-channel gene.

  B.  A patient whose blood plasma vasopressin levels are always very high due to a tumor whose cells are vasopressin-containing neurosecretory cells that continuously secrete high levels of vasopressin into the blood plasma.

  C.  A patient with neurogenic diabetes insipidus who produces no vasopressin.