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
A 60 year old woman was bedridden for 2 months complains of breathlessness & chest pain, chest X-ray is normal.
Next step is 
Select and explain. 
A. V/Q scan, B. Echocardiography, C. Pulmonary wedge angiography, D. Pulmonary arteriography.
A: V/Q scan
Answer: A: V/Q scan 
Explanation: Clinical picture s/o P.embolism Next step should be CT Pulmo angiography - not there in option thus V/Q scan next best.