The correct answer is (E).
(E) Parallel Flaw
Step 1: Identify the Question Type
The correct answer will be an argument that is "parallel to" the one in the stimulus, which is described as flawed. That makes this a Parallel Flaw question. The correct answer must commit the exact same flaw as the argument in the stimulus.
Step 2: Untangle the Stimulus
The stimulus's author concludes that some soils contain clay and sand while other soils contain clay and organic material. This is because most soil contains clay, and almost all soil has sand or organic material.
Step 3: Make a Prediction
The problem here is that almost all soil contains sand or organic material. However, it's impossible to tell which one is more common. It's possible that 90% of soil has sand while only 9% has organic material (for a total of 99%Ñvirtually all soil having one or the other), yet clay might only appear in soil with sand (90%Ñstill most soil). Based on the two overlapping majorities, clay will certainly appear with sand or organic material, but there's no guarantee it will appear with sand in some soils and with organic materials in others, as the original argument concludes. The correct answer will make the same flawed shift from or to and. It might be helpful to set up an algebraic formula to compare the logic. The evidence is that most items (soils) have X (clay), and almost all those items have Y or Z (sand or organic materials). The conclusion is that some items have X and Y and others have X and Z.
Step 4: Evaluate the Answer Choices
(E) matches the flawed logic. The evidence is that most items (pharmacies) have X (cosmetics), and almost all those items have Y or Z (shampoo or toothpaste). The conclusion is that some items have X and Y and others have X and Z. Like the original, it's possible that 90% of pharmacies have shampoo and 9% have toothpaste, and cosmetics could be sold only where shampoo is sold. There's no guarantee it would also be sold with toothpaste.
(A) has perfect evidence. However, the conclusion is conditional, based solely on if cosmetics are sold with toothpaste. If cosmetics are sold with shampoo, the conclusion doesn't trigger anything. So, the conclusion leaves open the door that cosmetics could be sold without toothpaste, taking away part of the original's flaw.
(B) mixes up the evidence and conclusion, concluding that most pharmacies sell cosmetics based on evidence of what some pharmacies sell. A conclusion about most pharmacies cannot be drawn from evidence about some pharmacies, but that's not the same flaw as the original.
(C) matches the evidence. However, the conclusion here is actually logical, not flawed. This is saying that if there's no pharmacy with cosmetics and toothpaste, then there must be some with cosmetics and shampoo. In other words, there must be pharmacies with at least cosmetics and toothpaste or cosmetics and shampoo, not necessarily both. This properly retains the or in the logic from evidence to conclusion.
(D) has the correct conclusion, but it is based on different evidence, and thus does not match. Instead of evidence that almost all pharmacies have Y or Z (shampoo or toothpaste), the evidence here is that almost all pharmacies with Y also have Z. That ignores all the pharmacies that don't have YÑa flaw not found in the original argument.
