PT74.S1.Q17 - how the pigment known as han purple was synthesized

Matt2014

http://7sage.com/lsat_explanations/lsat-74-section-1-question-17/
Conclusion: Hans purple was probably created by accident while someone was trying to make white glass.

Reasoning: Hans purple uses the same chemical ingredients and a similar process as making white glass.

When I first came across this question, my eyes immediately made their way to answer choice D. D states that the ingredients involved in making Hans purple and white glass were easily obtainable during the relevant time period. I reasoned that if the ingredients were easily obtainable, then people may be less cautious, and thus, an accident is more likely to occur. I guess I was just focused on the word, "accident".

But A is correct because it ties the two creations geographically. I understand this is a "hidden assumption"--if Hans purple was made on accident while someone was trying to make white glass, then it helps if the two come from the same place.

How did you guys fare on this question? Did you spot the problem immediately? I was also thrown off by the phrase, "small geographical region" in answer choice A. I thought to myself, "Who cares if it's a small region? Irrelevant."

ddakjiking

Bumping this because I did PT 74 today and finally experienced this infamous question. Upon my first read, I quickly eliminated my choices down to A and D. I read the stimulus and argument core a second time and my reasoning happened to go with A and the subtle assumption.