Answer: A. Endothermic
Step-by-step explanation:
In an endothermic reaction, heat is sucked in from the surrounding area by the reactants so that they may use it to react and form new products. This will therefore reduce the temperature in the said surrounding by the amount that the reaction needed.
This is what ice does when it melts. It sucks in the heat surrounding the area and then melts but leaves the area colder. For instance, putting ice in water ensures that the ice melts but because it sucked in the heat from the water to do so, the water gets colder as a result.