It overlooks the possibility that many people may prefer Sparkle Cola to competing colas for reasons such as the packaging or price of Sparkle Cola, rather than its taste. It takes for granted that most of the volunteers would buy Sparkle Cola rather than one of the other colas tasted, at least in situations where Sparkle Cola is not much more expensive. It overlooks the possibility that a generalization true of the entire group of volunteers was not true of each of the five smaller groups. It is based on a study that does not elicit consumers' responses to any beverages other than colas.
Advertisement: In a carefully controlled study, blindfolded volunteers were divided evenly into five groups. Each volunteer tasted Sparkle Cola and one of five competing colas, each group tasting a different cola. Most of the volunteers said they preferred Sparkle Cola to the competing cola tasted. This shows that Sparkle Cola elicits a more favorable response from consumers than any of the competing colas tested.
The reasoning in the advertisement is most vulnerable to criticism on which one of the following grounds?