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: Forensic Medicine
A man operated for fracture femur developed dyspnea, severe chest pain, streaky hemoptysis and hypotension on 4th day, cause is: UPSC 11; KCET 12 
Select and explain. 
A. Air embolism, B. Fat embolism, C. Pulmonary embolism, D. Meningitis
B: Fat embolism
Answer: B: Fat embolism 
Explanation: Ans. Fat embolism