This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vascular surgery, Subject name: Surgery
[{'content': 'The deficiency of all the following factors increases the incidence of thrombus formation except \nSelect and explain. \nA. Lipoprotein A, B. Protein C, C. Anti-thrombin III, D. Protein-S', 'role': 'user'}, {'content': "Answer: A \nExplanation: . Because deficiencies of antithrombin III,protein C ,pritein S,factor V of Leiden,thrombophila etc are the causes of thrombus formation. Refer page no 223 of SRB's manual of surgery 5th edition.", 'role': 'assistant'}]