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: Medicine
Best investigation when there is clinical suspicio of pulmonary embolism in a patient is - 
Select and explain. 
A. D - Dimer assay, B. Multi detector CT angiography, C. Doppler ultrasound, D. Catheter angiography
B: Multi detector CT angiography
Answer: B: Multi detector CT angiography 
Explanation: None