A 51-Year-Old Woman Comes to the Emergency Department Due to Fever

A 51-year-old woman comes to the emergency department due to fever and generalized weakness.  She was diagnosed with metastatic ovarian cancer 3 months ago and is on systemic chemotherapy after undergoing cytoreduction surgery.  Cycle 2 of chemotherapy was completed 10 days ago.  The patient initially had nausea and vomiting but was feeling better the last few days.  However, yesterday afternoon she became quite fatigued, and this morning she had a temperature of 39.1 C (102.4 F) .  Her oncologist recommended a visit to the emergency department for evaluation.  The patient has had no sore throat, sinus pain, cough, shortness of breath, chest pain, diarrhea, or urinary symptoms.  She has no other chronic medical problems but had prolonged neutropenia after her first cycle of chemotherapy.  She does not use tobacco or alcohol and has no known drug allergies.
Temperature is 38.6 C (101.5 F) , blood pressure is 110/70 mm Hg, pulse is 112/min and regular, and respirations are 20/min.  Pulse oximetry shows 96% on room air.  The patient is alert and cooperative.  No lymphadenopathy is present.  There is no skin rash or erythema or tenderness around the subcutaneous venous access device.  Lungs are clear to auscultation, and no heart murmurs are present.  The abdomen is soft and nontender.  Neurologic examination shows no abnormalities.
Laboratory results are as follows:
Chest-x ray reveals no new parenchymal opacities or pleural effusion.  Urinalysis reveals no pyuria.  Two sets of blood cultures are drawn and intravenous fluids are administered.
Which of the following is the best initial treatment for this patient?

A) Intravenous cefepime and vancomycin
B) Intravenous ceftazidime and ciprofloxacin
C) Intravenous piperacillin-tazobactam
D) Intravenous piperacillin-tazobactam and caspofungin
E) Oral trimethoprim-sulfamethoxazole