United States advertising agencies are increasingly using interviews at shopping malls, called, “mall intercepts” to test for advertising effectiveness, products viability, and consumer buying habits. Critics of mall intercepts maintain that the shopping habits of mall shoppers are not representative of those of the larger populations.

Which of the following argument most strengthens the viewpoint of the critics?

Some mall shoppers patronize more than one mall in any given shopping trip.

Mall shoppers, on average, spend 50 percent more time shopping than shoppers at other locations do.

In the course of any year, 95 percent of all households in the United States have at least one member who does some shopping at a mall.

Mall shopper who use public transportation to reach the mall tend to have lower incomes than mall shoppers who drive to the mall.