Review Question - QID 210796

A 29-year-old woman comes to the emergency room with a 4-day history of fever and worsening cough. She describes bringing up a purulent, yellow sputum when she coughs. The patient has a history of cystic fibrosis and works as an elementary school teacher. The patient’s temperature is 102.3°F (39.1°C), blood pressure is 113/73 mmHg, pulse is 98/min, respirations are 18/min, and oxygen saturation is 94% on room air. She is sitting up in bed and sweating. A physical exam reveals bilateral crackles and decreased breath sounds with dullness to percussion in the right lung base. A chest radiograph is obtained and reveals a right lower lobe consolidation. Which of the following is the most likely causative agent?