Endothermic vs. Exothermic
Chemical reactions can be regarded as either endothermic reactions or exothermic reactions. The two terms describe the direction in which energy is transferred across the boundary between
the system (reactant and product chemicals) and
the surroundings (everything else in the universe). In an
endothermic reaction, energy is transferred from the surroundings to the system of chemicals. This gain in energy by the system is required in order for the reaction to occur. In an
exothermic reaction, energy is released by the system of chemicals to the surroundings. This loss of energy from the system occurs because the energy of products is less than the energy of reactants.
These concepts of endothermic and exothermic can be represented in a variety of ways. The graphic below communicates the connection between these terms and the variety of ways they are represented.
Get a Game Plan
Sometimes all you need is a good game plan - the proper approach. In this question, a good game plan would involve identifying each representation as being representative of either an endothermic reaction or an exothermic reaction. The top representation is easily translated as it directly states which it is. So use the graphic above and do the translation work for the other two. When done, you should have two exothermic representations and one endothermic (or vice versa). Then you will be able to make your decision.