Ans. B. Pulmonary angiographyAlthough pulmonary angiography is supposed to be the definitive and gold standard means of diagnosing PULMONARY EMBOLISM with the decreasing availability of pulmonary arteriography and increasing use of other non-invasive tests like spiral CT, the exact role of pulmonary arteriography is now less clear and there are only few indications for it, especially in absence of spiral CT or MRI.