This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
[{'content': 'The penaz technique \nSelect and explain. \nA. Is invasive, B. Uses plethysmography, C. Does not require a pneumatic cuff, D. Is suitable in presence of peripheral vascular disease', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Penaz technique is a continuous non-invasive method of BP monitoring. Infra-red plethysmograph is mounted on the pneumatic cuff.', 'role': 'assistant'}]