Final answer:
A pneumothorax would appear on a chest x-ray film as more radiolucent than normal lung. The affected lung would appear darker or more transparent compared to the unaffected lung.
Step-by-step explanation:
A pneumothorax would appear on a chest x-ray film as D. More radiolucent than normal lung. A pneumothorax occurs when air leaks into the space between the lung and chest wall, causing the lung to collapse partially or completely. On a chest x-ray, the affected lung would appear darker or more transparent compared to the unaffected lung due to the presence of air instead of lung tissue.