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: Radiology
Pulmonary embolism is diagnosed by: 
Select and explain. 
A. USG, B. X-ray chest, C. Ventilation perfusion scan, D. CT scan
D: CT scan
Answer: D: CT scan 
Explanation: Ans. CT scan