<prompt> Which of the following statement best describes an Orphan drugIt is a drug which acts on orphan receptorsIt is a very cheap drugIt is a drug which has no therapeutic useIt is a drug declared for treatment of prevention of a rare disease  <response>: Ref-KDT 6e p6 Orphan drugs are used for rare diseases. Eg.erythroprotein for the treatment of anemia in patient with chronic renal failure 