Calorimeter is an instrument which is used for measurement of heat liberation or absorption from a system during the flow of energy.
Answer: Option A
Step-by-step explanation:
When the heat is liberated from the system, during the flow of energy it undergoes a exothermic reaction. Similarly, when the heat is absorbed by the system during the flow of energy, the system undergoes an endothermic reaction.
The calorimeter as the name suggest is the meter to calibrate calorie. Calorie here refers to the heat energy, which is being calibrated or measured during the flow of energy, either liberated from the system or being absorbed by the system.