You are answering a USMLE-style medical question. Question: A 3-year-old boy presents to the emergency department with a ‘cough-like-a-seal bark’ and a high-pitched inspiratory noise that is audible without a stethoscope. His mother reports that his cough has worsened over the last few hours. The patient's blood pressure is 118/78 mm Hg, pulse is 90/min, respiratory rate is 35/min, and temperature is 38.3°C (101.1°F). On physical examination, the boy is sitting and leaning forward in apparent respiratory distress with suprasternal and intercostal retractions. Auscultation reveals inspiratory stridor without wheezing. He has a frequent barking cough and a hoarse voice when he speaks. What is a chest X-ray likely to show? Options: A) Increased interstitial markings B) Lobar consolidation in the lingual C) Thumbprint sign on the lateral image D) Steeple sign Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.