A client with leukemia is undergoing a bone marrow biopsy for diagnosis and staging. The nurse should explain that the primary purpose of this procedure is to:

A) This choice is incorrect because stem cells used in transplantation are typically not extracted from the client's cancerous tissues.

B) This choice is correct. In a stem cell transplant, stem cells are collected from the bone marrow of a matched donor (allogeneic transplant) or the client themselves (autologous transplant). These stem cells are then infused into the client's bloodstream to replace the damaged bone marrow and produce healthy blood cells.

C) This choice is incorrect because stem cells used in transplantation are not taken from a tumor.

D) This choice is incorrect because stem cells used in transplantation are not harvested from the client's peripheral blood.

A) This choice is correct. A lumbar puncture is performed to assess cerebrospinal fluid (CSF) for the presence of leukemic cells in cases where leukemia may have spread to the central nervous system. This procedure helps determine if the client requires specific treatment to target leukemia in the CNS.

B) This choice is incorrect because a lumbar puncture is not primarily used to evaluate liver and kidney function.

C) This choice is incorrect because measuring blood glucose levels is not the primary purpose of a lumbar puncture.

D) This choice is incorrect because determining the client's platelet count is not the primary purpose of a lumbar puncture. Platelet counts are typically obtained through a blood test.