Jill is in the market for purchasing a new automobile, but she will only consider models made by American companies. The American car makers are part of Jill's set.

Evoked set.

Explanation:

An evoked set is a group of items, materials, characteristics or traits of things of certain brands with which an invididual feels most comfortable with at the moment of purchasing something. For example, when Jill looks for a new automobile, she considers the models made by American companies, making those companies part of her evoked set.