Concept: Consumerism focuses on safeguarding the interests and rights of buyers in the marketplace.Explanation: Consumerism is a movement that seeks to protect consumers from unfair, unsafe, or deceptive business practices. Its primary function is to ensure that consumers are informed, respected, and free from exploitation. This is achieved by promoting and enforcing consumer rights, such as the right to safety, information, and redress. Therefore, the key function is to protect the interests of consumers.Answer: A. Protecting consumers' rights