Answer:
A. Calorimeter
Explanation:
A calorimeter is an apparatus that can be used to measure the quantity oh heat in a chemical reaction or the amount of heat that accompanies a physical change and also determine the specific heat capacity of a substance.
It is used extensively in physics, chemistry and the study of thermodynamics. In its simplest form, a calorimeter contains a thermometer which is attached to a container filled with water and suspended above a combustion chamber.