The temperature of an aqueous solution decreases when solid ammonium nitrate is dissolved in water. Which term best describes this dissolution process from the perspective of the system?
(a) Exothermic, because the system absorbs heat from the surroundings.
(b) Endothermic, because the system releases heat to the surroundings.
(c) Endothermic, because the system absorbs heat from the surroundings.
(d) Exothermic, because the system releases heat to the surroundings.