A Patient Is Prescribed Ranitidine (Zantac)

A patient is prescribed ranitidine (Zantac) .The nurse checks the patient's BUN and serum creatinine levels prior to administering the drug for the first time.The rationale for checking these labs is:

A) The drug is primarily biometabolized by the liver.
B) Serum BUN and creatinine should be checked on all patients.
C) To identify a hidden drug allergy.
D) The drug is primarily excreted by the kidneys.