A Calorimeter Is Used to Measure the Energy Content of Foods

A calorimeter is used to measure the energy content of foods because the energy measurement obtained using a calorimeter is the same as the energy we obtain by eating.Which of the following statements explains why this is the case?

A) They are the same because both the calorimeter and body combust food to obtain only heat energy.
B) They are the same because both the calorimeter and body combust food in a single exothermic step.
C) They are the same because both the calorimeter and body combust food in a complex series of steps.
D) They are the same because, overall, metabolism is a combustion reaction.
E) Actually, they are not the same values.