This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fundamental Concepts, Subject name: Anaesthesia
[{'content': 'Compression depth in CPR in Adults is? \nSelect and explain. \nA. 1 inch, B. 2 inch, C. 3 inch, D. 4 inch', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) 2 inchRef: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations CoSTR', 'role': 'assistant'}]