I see so many MSS questions when I try the hardest level, and I’ve started feeling confused about how to differentiate Principle questions from PSA or MSS. Is anyone else having the same issue?

I'm surprised that there are only two comments on this question! I also picked C originally thinking that the human intelligence didn't change even after successfully applying computer programs to other games, which then could prove that the claim was "wrong." However, the question here is not about whether the claim is right or wrong.

The most important point from the argument is how 'chess' and 'human intelligence' are somehow connected, which is the weakest link. C links chess with some other games, skipping the part how it's connected to 'human intelligence,' so D is the right answer. I hope this makes sense!