A 28-year-old woman presents to the emergency department with a 3-day history of fever, productive cough with purulent sputum, and dyspnea. She has a history of cystic fibrosis. On examination, she is febrile (38.5°C), tachypneic (RR 28/min), and has crackles in the right lower lobe. Sputum culture grows Pseudomonas aeruginosa. She has normal renal function (creatinine 0.8 mg/dL). Which of the following beta-lactam antibiotics is most appropriate for this patient?