Final answer:
An increase in temperature shifts the equilibrium to favor an endothermic reaction because it adds energy to the system, which the endothermic process then absorbs. The correct answer is option A.
Step-by-step explanation:
An increase in temperature always shifts the position of an equilibrium to favor an endothermic process. The correct answer to the student's question is (a) Increase. This is because increasing temperature can be thought of as adding energy to the system.
In the context of chemical equilibrium, for an endothermic reaction, where energy is absorbed, this addition of energy shifts the equilibrium towards the product side as the system attempts to absorb the extra energy by favoring the endothermic process. Conversely, for an exothermic reaction, an increase in temperature would shift the equilibrium towards the reactants to release energy, as heat is a product of these reactions.