Luster is the correct answer.
NaOH will dissociate as Na+ and OH- in the solution.
The potential energy of the products is higher than the potential energy of the reactants.
A should be the answer because the more you test an experiment the more data you have to rely on changing the experiment would cause you to have different outcomes making the results different and unreliable so B, C, and D is not going to be the answer Hope this helps