According to the Consumer Reports article in Resource R$2,$ in order to conduct their scientific study, $$we had an outside lab test $382$ chickens bought last spring from more than $100$ supermarkets, gourmet$-$ and natural$-$food stores, and mass merchandisers in $22$ states. We tested three top brands$$Foster Farms, Perdue, and Tyson$$as well as $30$ nonorganic store brands, nine organic store brands, and nine organic name brands.$$

Check one below, stating whether this use of various brands and types of poultry would be an example of a $$dependent$$ or $$independent$$ variable.