The set of marketing tools a firm uses to implement its marketing strategy is called the

Marketing mix.

Explanation:

Marketing mix is defined as a set of elements that make up marketing actions in an organization. According to Kotler, the purpose of the marketing mix is to help the company achieve its goals in the market by using a set of marketing tools.

There are several models developed to represent the marketing mix, but the most used by organizations is represented by four essential pillars for the development of any marketing strategy, which are the 4P's of marketing: product, price, place and promotion. For each variable there are distinct and relevant activities:

in terms of experimental research, mcdonald’s charging different prices in the two cities relates to