This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
A patient with multiple injuries exhibit paradoxical chest movements during inspiration and expiration due to? 
Select and explain. 
A. Pneumothorax, B. Flail chest, C. Cardiac temponade, D. Hemothorax
B: Flail chest
Answer: B: Flail chest 
Explanation: None