The correct answer is "boycott." A boycott is a form of protest where individuals or groups voluntarily decide not to use, buy, or support a particular product, service, company, or organization, typically due to ethical, social, or political reasons. To determine the correct answer, you can use your knowledge and reasoning, or you can search for the term "boycott" online or in a reliable source like a dictionary or encyclopedia.
To refuse to use or buy something as a protest is known as a boycott.