If a nationwide sandwich shop introduces a new sandwich in the Midwest to try out its marketing strategy before offering the product across the country, it is in the stage of the product development process.

test

Explanation:

Based on the information provided within the question it can be said that in this scenario the shop seems to be in the test marketing stage of the product development process. This is the stage in which a business places their product in a simulated scenario based on how the real-life buying situations will be, in order to evaluate how their product will perform in the market.

answer(eu) is the correct answer;

answer (b); /// a method of measuring the opinions of a large group of people by selecting a subset of the larger group, asking them a set of questions and then generalizing those responses;