<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A previously healthy 21-year-old man is brought to the emergency department 4 hours after the sudden onset of shortness of breath and pleuritic chest pain. He has smoked 1 pack of cigarettes daily for the past 3 years. He is 188 cm 6.2 ft tall and weighs 70 kg 154 lb; BMI is 19.8 kgm2. Physical examination shows decreased tactile fremitus and diminished breath sounds over the left lung. Which of the following is the most likely cause of this patients symptoms?? A: Embolic occlusion of the pulmonary artery, B: Rupture of a subpleural bleb, C: Infection with gram-positive diplococci, D: Hyperresponsiveness of the bronchial system, E: Inflammation of the costal cartilage,  <response>: This is a clinical vignette describing a young adult male with acute onset of shortness of breath and pleuritic chest pain. Key findings include 3 year history of smoking, decreased breath sounds on the left lung, and pleuritic chest pain. The most likely diagnosis is a spontaneous pneumothorax given the patients age, smoking history, and unilateral decreased breath sounds. A pneumothorax is caused by rupture of subpleural blebs which can occur in young, tall, thin males who smoke. This results in air accumulating in the pleural space causing chest pain and shortness of breath. Embolic occlusion of the pulmonary artery is unlikely given the patients age and lack of risk factors. Infection is less likely without fever or productive cough. Bronchial hyperresponsiveness may cause wheezing but not unilateral decreased breath sounds. Costal cartilage inflammation is implausible.B: Rupture of a subpleural bleb 