This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bleeding Disorders, Subject name: Pathology
[{'content': 'Warfarin skin necrosis is caused by- \nSelect and explain. \nA. Protein C/Protein S deficiency, B. APLA, C. Vitamin K deficiency, D. Fibrinogen deficiency', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) Protein C/Protein S deficiency(Ref: Wintrobe's 12th/pg 1490)Warfarin skin necrosisDue to warfarin-induced rapid reduction in protein C levels in patients with a pre-existing inherited protein C deficiency that results in a hypercoagulable state and thrombosis.Not all heterozygous protein C-deficient patients receiving warfarin experience this complication, and not all patients with this complication have protein C deficiency.", 'role': 'assistant'}]