#help
Dear all,
I have a hard time to be fully convinced of why AC B is a necessary assumption.
I'm mostly disturbed by the phrase "most commonly grown". I would have interpreted the modifier "commonly grown" as the non-new potato strains, and then B would obviously be the correct answer (since, if the non-new strains could have produced the same yields as 20 years ago, it would wreck the argument). But isn't "most commonly grown" a modifier which indicate a subset of those non-new potato strains? If so, the negation of that assumption could still be compatible with the argument (e.g. if this subset comprised 55% of the potatoes 20 years ago, that is 55 million tons, then even if it did reach the 55 million tons the argument would still hold).
Thanks!