Final answer:
A bomb calorimeter is the device used to measure the energy content of foods by burning a sample under high-pressure oxygen and measuring the resultant temperature increase. Option A is correct.
Step-by-step explanation:
The correct device used to measure the energy values of foods in a laboratory is a bomb calorimeter. A bomb calorimeter is a device designed to measure the energy change for processes occurring under conditions of constant volume. This is commonly done for reactions that involve combustion, such as determining the caloric content of food.
When measuring the energy content of food, the food sample is placed in the calorimeter, which is then filled with oxygen under high pressure. An electric spark ignites the food-oxygen mixture and as the food burns, it releases heat. The amount of heat produced is absorbed by the steel container and the water surrounding it. The resultant temperature increase is then used to calculate the calories present in the food, making use of known mathematical relations, the specific heat, and the mass of the calorimeter setup.