A pneumothorax can be caused by which of the following? (Select all that apply.)

Rationale: A. Rupture of a bleb is correct because spontaneous pneumothorax often occurs when a subpleural bleb ruptures, allowing air to escape into the pleural space and causing lung collapse. This is commonly seen in young, tall, thin individuals or patients with underlying lung disease. B. Lung abscess is incorrect because a lung abscess is a localized infection with pus formation within lung tissue. While it causes inflammation and destruction of lung parenchyma, it does not typically introduce air into the pleural space unless it ruptures, which is uncommon and not considered a primary cause of pneumothorax. C. Central line placement is correct because iatrogenic pneumothorax can occur during procedures such as subclavian or internal jugular central venous catheter insertion if the pleura or lung is accidentally punctured. D. Dyspnea is incorrect because dyspnea is a symptom, not a cause. It commonly occurs as a result of pneumothorax but does not cause one. E. Trauma is correct because blunt or penetrating chest trauma (such as rib fractures or stab wounds) can allow air to enter the pleural space, leading to a traumatic pneumothorax.