A 50-year-old man who is a nonsmoker comes to the office because of fever, productive cough, dyspnea, and occasional pleuritic chest pain that started yesterday. He thinks it is just a bad cold because "Colds are going around the office but my wife insisted I get checked." He has no history of pulmonary disease. On auscultation of the lungs you note focal lung findings including crackles, decreased breath sounds, and egophony. Which of the following is the most likely diagnosis?

A. Acute bronchitis
B. COPD
C. Heart failure
D. Community acquired pneumonia