Q. A 30-year-old man presents to your primary care clinic with a persistent dry cough and chest discomfort that has been bothering him for the past week. He states that he experienced symptoms of a common cold with a fever before the onset of the cough. His temperature is 98.6°F (37°C), pulse is 80 beats per minute, blood pressure is 120/80 mmHg, and respiratory rate is 14 per minute. Oxygen saturation is 98% on room air. During the physical examination, rhonchi are heard on auscultation in the lower lung fields, which get cleared when the patient coughs. No signs of consolidation are observed. Chest X-ray is normal. What is the most probable diagnosis for this patient?