C. released or absorbed.
When the energy is released the reaction is called exotermic reaction
When the energy is absorbed, the reaction is called endothermic reaction
An example of exotermic reaction is between water and H2SO4
Answer:Iron is extracted from iron ore in a huge container called a blast furnace. Iron ores such as haematite contain iron(III) oxide, Fe 2O 3. The oxygen must be removed from the iron(III) oxide in order to leave the iron behind. Reactions in which oxygen is removed are called reduction reactions.