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
Best method to diagnose pulmonary embolism: 
Select and explain. 
A. Pulmonary angiography, B. Scintillation perfusion scan, C. CT scan, D. X-ray chest
A: Pulmonary angiography
Answer: A: Pulmonary angiography 
Explanation: A i.e. Pulmonary angiography