Dog food should not include products containing gluten

VERITAS PREP OFFICIAL SOLUTION:

The conclusion of the argument above is that “dog food should not include products containing gluten” and the evidence given to support that conclusion is a study comparing two dog foods that seems to show wheat causes problems. However, no proof is actually given that it is the gluten-containing wheat in Farmer’s Delight food that is actually causing the intestinal issues and general malaise in the dogs. This is a classic case of mistaking correlation for causation. What if the intestinal issues and malaise were being caused by some other ingredient that is different between the two foods? Perhaps the meat in Farmer’s Delight is chicken, a common cause of intestinal issues in dogs, while Call of the Wild contains only salmon and veal. The wheat might have not been causing problems but the chicken was. Any answer choice that eliminates other possible causes for the issues with Farmer’s Delight as compared to Call of the Wild would be correct. Answer choice (C) eliminates one such possible difference, thus improving the possibility that wheat was the cause and making it the correct answer. For (A), this might seem to improve the argument at first glance, but you don’t know if that is a difference from Call of the Wild. If they both contain organic meat of the highest quality then this does not strengthen the argument. For (B), veterinarians’ recommendations for “most animal diets” do not necessarily apply to dogs and this does not address the real gap within the argument. For (D), this certainly addresses a flaw in the argument but it actually weakens the argument instead of strengthening it. The conclusion states that “dog food should not include products containing gluten” but then uses as evidence a food with 50% wheat. What if a food with a lower amount does not cause problems? Then it would be ok to have some gluten in dog food. Answer choice (D) suggests that a lower amount might not cause problems but this weakens the argument and the goal is to strengthen it. For (E), if dog food contains wheat with more gluten than other wheat this has no effect on the comparison between the two dog foods and is thus irrelevant. The correct answer is (C).