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
[{'content': 'Most specific investigation in disseminated intravascular coagulation is - \nSelect and explain. \nA. D - dimer assay, B. Bleeding time, C. Clotting time, D. Fibrinegen level', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]