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: Orthopaedics
After an operation on femur bone, chest x-ray shows widespread mottling throughout the lung field like a snowstorm, the likely cause 
Select and explain. 
A. Air embolism, B. Bacterial pneumonitis, C. Fat embolism, D. Pulmonary embolism
C: Fat embolism
Answer: C: Fat embolism 
Explanation: None