<prompt> In which of the following conditions that cause polycythemia is the serum erythropoietin extremely low -DehydrationRenal cell carcinomaRenal cell carcinomaPolycythemia vera  <response>: In polycythemia vera unlike secondary polycythemia erythropoietin levels in serum and urine are reduced. Reference textbook of Pathology 7th edition author Harsha Mohan page number 339 