The nurse prepares to administer temozolomide (Temodar) to a 59-year-old white male patient with a glioblastoma multiforme (GBM) brain tumor. What should the nurse assess before giving the medication?

A. Serum potassium and serum sodium levels
B. Urine osmolality and urine specific gravity
C. Absolute neutrophil count and platelet count
D. Cerebrosprinal fluid (CSF) pressure and cell count