A 58-year-old man with hypertension and type 2 diabetes presents with a 4-day history of fever, productive cough with rust-colored sputum, and right-sided pleuritic chest pain. Examination shows temperature 39.0??C, HR 110, RR 24, BP 128/78, and crackles in the right lower lobe. Chest X-ray confirms a lobar consolidation in the right lower lobe. He has no drug allergies and is otherwise healthy. Which of the following is the most appropriate initial outpatient antibiotic regimen?