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
Boy with sickle cell trait.. what mode of anaesthesia will u avoid in him?? 
Select and explain. 
A. IVRA (intravenous regional anesthesia), B. Supraclavicular brachial plexus block, C. Br plexus block infraclavicular approach, D. Br plexus block axillary approach (humeral) approach.
A: IVRA (intravenous regional anesthesia)
Answer: A: IVRA (intravenous regional anesthesia) 
Explanation: Intravenous Regional Anaesthesia or Biers block absolute C/I 1. Sickle cell trait 2. peripheral vascular Disease 3. Scleroderma