The thermal equivalent of oxygen of food is（ ）

A、1 gram of energy released when food is oxidized
B、The energy released when food is oxidized to consume 1 liter of oxygen
C、Energy released when 1 liter of oxygen is consumed by oxidizing 1 gram of food
D、1 gram of energy released by food during its metabolism in the body
E、1 gram of heat produced when food is burned outside the body