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
Body water content in percentage of body weight is lowest in - 
Select and explain. 
A. Well-built man, B. Fat woman, C. Well nourished child, D. Fat man
B: Fat woman
Answer: B: Fat woman 
Explanation: Lean tissues such as muscle and solid organs have higher water content than fat and bone. Thus, young lean males have a higer proportion of body weight as water than elderly or obese persons. Females as such have a lower percentage of total body water because of less muscle mass and more fat.