This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thermal injury, Subject name: Forensic Medicine
[{'content': 'When a palm is used as a measuring scale in estimating the burnt area, it is equal to \nSelect and explain. \nA. 1% of body surface area, B. 3% of body surface area, C. 4.5% of body surface area, D. 9% of body surface area', 'role': 'user'}, {'content': "Answer: A \nExplanation: Rule of palms: The surface area of a patient's palm (including fingers) is roughly 1% of TBSA. Palmar surface can be used to estimate small burns (< 15% TBSA) or very large burns (> 85%, when unburnt skin is counted). Ref - Srb's manual of surgery 5th edition , burns", 'role': 'assistant'}]