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 best diagnosed by: 
Select and explain. 
A. ECG, B. Perfusion scan, C. Angiography, D. Plain X-ray
C: Angiography
Answer: C: Angiography 
Explanation: Ans. Angiography