This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inhalational Anesthetic Agents, Subject name: Anaesthesia
[{'content': 'Boy with sickle cell trait.. what mode of anaesthesia will u avoid in him?? \nSelect and explain. \nA. IVRA (intravenous regional anesthesia), B. Supraclavicular brachial plexus block, C. Br plexus block infraclavicular approach, D. Br plexus block axillary approach (humeral) approach.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Intravenous Regional Anaesthesia or Biers block absolute C/I 1. Sickle cell trait 2. peripheral vascular Disease 3. Scleroderma', 'role': 'assistant'}]