Leslie Bradley is an entrepreneur with a small business in Little Rock, Arkansas. Working with a local engineer/inventor, Leslie has developed a new cooking device that she thinks will revolutionize cooking. The device is a small oven that is portable and uses a gas injection system to cook meals in a fraction of the time taken in a normal oven. The new system creates a very high temperature and the gas jets are located 360 degrees around the food to be cooked, thus ensuring that the food is cooked equally on all sides. Leslie and the engineer applied for a patent and then immediately sought a relationship with a large manufacturer to produce and distribute the new oven. To her surprise, when she demonstrated it to the top three manufacturers, they all had the same reaction: "We are very interested in this new invention but we would like to see some consumer research that tells us what consumers think about the device." "Will they think the temperature is too high and represents a safety issue?" "Do they really think that a roast cooked in 6 minutes will taste the same as one roasted for 2 hours?" "How much, if any, will they be willing to pay for the added convenience of time savings?" Leslie sought the services of Weber Research, Inc. WRI was an established research firm in the city and they recommended that they use their mall facility in order to conduct some research that allowed consumers to use the device and taste the food cooked in the device. Leslie agreed but was concerned about the types of persons in the shopping mall. "They really won't represent our area since they will likely be mostly female and they will have higher incomes than the general population."
WRI assured Leslie that this could be overcome by using which of the following sampling methods?

A) quota sample
B) purposive sample
C) stratified sample
D) representative sample
E) systematic sample