By applying Le Châtelier’s principle to a reaction that has come to equilibrium, the reaction can be made to

A. produce more reactants.
B. run to completion.
C. reach a new chemical equilibrium.
D. All of the above
Is the answer D?

Probably I would answer D also; however, although we talk about reactions going to completion(answer B), technically, that is never true. Reactions that proceed so far to the right that they are 99.99% complete falls into "essentially complete" and we call them complete. I think the spirit of the question is for us to assume that to be the same as completion.

Yes, the correct answer is D. By applying Le Châtelier’s principle to a reaction at equilibrium, the conditions can be changed in order to favor the formation of either more reactants or more products. This can be achieved by altering the temperature, pressure, or concentration of reactants or products, or by adding a catalyst. Therefore, the reaction can be made to produce more reactants, run to completion, or reach a new chemical equilibrium, depending on the changes applied.

Yes, the correct answer is D. All of the above. By applying Le Châtelier's principle to a reaction at equilibrium, it is possible to shift the equilibrium in such a way that the reaction can produce more reactants, run to completion, or reach a new chemical equilibrium. Le Châtelier's principle states that a system at equilibrium will respond to any changes imposed upon it in order to minimize the effect of those changes and restore equilibrium.