This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thermal Deaths, Subject name: Forensic Medicine
Rule of 9 in burns is used to denote - 
Select and explain. 
A. Depth of bums, B. % of total body surface area, C. Severity of bums, D. Type of bums
B: % of total body surface area
Answer: B: % of total body surface area 
Explanation: Ans. is 'b' i.e., % of total body surface areao Rule of 9 (Wallace's formula) - it is used for estimation of bum area The surface area burnt is more important than the degree of bum, in assessing prognosis of a given case. For example, a first degree bum over a wide area is more dangerous than a third degree bum over a limited area.Area of bodyIn Children (Lund and browder chart)In Adults (Rule of nine: Wallace's formula) 1-4 years5-9 years10-14 yearsAdultHead and Neck1915139Trunk (front)16161618 (Front of chest + abdomen)Trunk back16161618 (Back of chest + abdomen)Upper limbs19191918 (Right+left upper limbs)Lower limbs30343536 (Front+back of right and left lower limbs)Genitals0011