Which of the following individuals is most likely to be in a negative nitrogen balance?

A) A healthy pregnant woman
B) A 10-year-old child
C) An adult woman with adequate protein intake
D) An elderly homeless man
E) A healthy adult man who exercises

A negative nitrogen balance occurs when the output of nitrogen exceeds the intake, often seen in conditions of malnutrition, illness, or stress. An elderly homeless man is most likely to experience inadequate nutritional intake, including insufficient protein, leading to a negative nitrogen balance.