The origin of a food prohibition must be explained with reference to the understanding that the people who adopted
Why this is right
This answer sounds potentially too strong: must be explained. But, the author's conclusion justifies that strong wording, since she's saying "these data cannot explain the origin of the prohibitions". Let's consider her argument move, and then contrapose it: ppl who adopted and this data can't enforced taboos didn't → explain origins have access to this data of taboo The contrapositive would look like this, in order for data to explain the origin of a food prohibition, then the people who adopted and enforced the taboo must have had access to this data. That's essentially what this answer choice is saying, only instead of saying "access to this data", it's saying "an understanding of this data". If we negated this answer, would it weaken the argument? When explaining the origin of a food taboo, you don't need to consider the understanding of the people who adopted/enforced the taboo. That definitely weakens the argument, because it's saying that the Author's premise isn't really essential to the conclusion. The author is acting like, "this data can't possibly explain Y, because the people who created Y didn't know about the data". And this negation would be objecting, "We don't need to worry about whether or not the people who created Y understood the data in order to explain the origin."
Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.