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: Surgery
[{'content': 'According to “rule of nines”, burns involving perineum are: \nSelect and explain. \nA. 1%, B. 9%, C. 18%, D. 27%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Burn Size (% BSA)\n\nDetermination of burn size estimates the extent of injury.\nBurn size is assessed by Wallace rule of nines (By Alfred Russel Wallace)\n\nWallace Rule of Nines:\n\nIn adults:\n\n- Each upper extremity: 9%\n- Head and neck: 9%\n- Lower extremities: 18%\n- Anterior and posterior aspects of the trunk: 18%\n\xa0 \xa0 \xa0 - Perineum and genitalia: 1%\n\nChildren have a relatively larger proportion of body surface area in their head and neck, which is compensated by a relatively smaller surface area in the lower extremities.\n\n\xa0- In infants: Head and neck- 21%; Each leg-13%\n\nBerkow formula is used to accurately determine burn size in children.\nFor estimating smaller burns: Area of open hand (including palm and extended fingers) of the patient is approximately 1% of TBSA.\nThis method is helpful in evaluating splash burns and burns of mixed distribution.', 'role': 'assistant'}]