ugh I can't tell why the right answer is correct, but I can feel why the wrong answers are incorrect

This is so random, but I remember three months ago when I started my journey in studying for the LSAT I had absolutely no idea how to approach these questions. I would read the stimulus and look at the answer choices and basically select something random because I had no idea what the question was even asking me to do. Three months later after going through the core curriculum and really just trying to dissect each of the question types and understand what the question stem is asking and what the stimulus is saying, I have gotten every single drill question correct up to this point and I couldn't be prouder of myself. I have never gotten a 5-difficulty question correct, and this was the first one I ever got, even with it being a SA question, which is one of the most difficult question types for me. Just don't lost motivation, you got this. I have been really down on myself because I haven't been able to study every day, and I'm worried this is hindering me from reaching my full capability. But really, all that matters is that you are improving, and if I can do it surely anyone can LOL. I teared up a little at seeing my progress.

UGH I got it right at first but overthought my answer in the blind review. I thought that because the stimulus mentioned that the experimenters used techniques that were traditional to the area, that this implied that such techniques have been around for a while, thereby making answer choice A sound redundant.

#help is it possible to ascertain the answer by mapping it out as a conditional? I'm not sure if this is a reasonable method but somehow, I ended up at the correct answer choice by doing this.

holy crap shallow dip SAVED me !!!!!