This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'D-dimer is the most sensitive diagnostic test for \nSelect and explain. \nA. Pulmonary embolism, B. Acute pulmonary oedema, C. Cardiac tamponade, D. Idiopathic pulmonary fibrosis', 'role': 'user'}, {'content': "Answer: A \nExplanation: The quantitative plasma D-dimer ELISA rises in the presence of DVT or pulmonary embolism because of the breakdown of fibrin by plasmin.The sensitivity of the D-dimer is >95% for pulmonary embolism.This test is less sensitive for DVT(80%) than for PE because the DVT thrombus size is smaller.But this assay is not specific.Levels increase in patients with MI,pneumonia,sepsis,cancer,post operative period & in the second and third trimesters of pregnancy. Reference:Harrison's medicine-18th edition,page no:2172.", 'role': 'assistant'}]