This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Regional anaesthesia, Subject name: Anaesthesia
[{'content': 'Most common complication of celiac plexus block \nSelect and explain. \nA. Pneumothorax, B. Postural hypotention, C. Retroperitoneal hamorrhage, D. Intra_aerial injection', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Postural hypotension : due to lumbar sympathetic chain blockade leading to upper abdominal vessel dilation and venous pooling. So intravenous fluids are required preblock', 'role': 'assistant'}]