A company is considering adding a new ingredient to its bread recipe to increase the freshness of the bread. To study the

The question was, "A company is considering adding a new ingredient to its bread recipe to increase the freshness of the bread. To study the impact of adding ingredient P, Q, R, S, or T to the recipe, they baked 270 loaves of bread. Some of the loaves contained no extra ingredients, while each of the rest contained one of the five new ingredients. The freshness of the bread was checked one week later, and the results were used to create the two-way tables below.

Which tables suggest an association between adding an extra ingredient and the freshness of the bread? Check all that apply."

The answer is C. D. and E. or the last three tables.

To study the what?