题目选项分析

Research has shown that protein should comprise about 18 percent of a dog’s diet. The best sources of protein are animal meat and fish. At the Calliston Pound in Centerville, dogs are fed a primarily grain-based diet. Clearly, this selection of food explains why many dogs at the Calliston Pound were found to be underweight or malnourished.

Which of the following, if true, most seriously weakens the argument?

【选项】The Calliston Pound is one of Centerville’s least populated animal shelters.