Bunuel
During the harvest season a farmer collects 45 kilos of apples per week from his orchard. The farmer claims that he sorts his crop and rejects 10 kilos from this quantity to ensure the same quality of apples every week.
Of the following, the best criticism of the farmer's plan is that the plan assumes that:
One thing about real GMAT questions is that language is used in a perfectly precise way, and often on harder questions, we really need to pay careful attention to the language, and interpret it exactly as it's written. But here, the wording is so careless it's hard to guess what the question means. In the stem the farmer "claims that he sorts his crop and rejects 10 kilos" of apples. Is that just a claim? Is it possibly false? I'd have to guess that the question means to tell us that it is a fact that this farmer discards 10 kilos of apples each week, and the only "claim" is that this will "ensure the same quality of apples every week". Then we are asked to criticize "the farmer's plan", but there is no "plan" mentioned anywhere. The stem mentions something the farmer claims to do, not something the farmer plans to do.
So it's hard to tell what kind of answer we're looking for, because it's hard to tell what the question is trying to ask. I assume we're looking for an answer that might explain why, by rejecting 10 kg out of 45 kg of apples each week, the farmer might not achieve the goal of having 'the same quality of apples every week". If so, we don't care about selling apples, or about improving their quality (we want the same quality, not better quality), so A and B aren't right. The plan assumes the opposite of D -- it assumes you can sort apples by quality -- so D is wrong. That leaves C and E, and I have no idea what answer choice C even means; what does it mean for an apple to be "worthy of being sorted"? I wonder if it is transcribed correctly. Anyway, E seems like it has to be the answer; just because we throw out the same quantity of apples every week doesn't mean the accepted apples will be the same quality every week. In fact, you'd expect as you get later in the apple season that the apples would change (I don't know anything about apples, but presumably they ripen) so you could reasonably expect the quality of the accepted apples will change too, and we won't have "the same quality" every week.