How can customers engage with Starbucks’ ethical sourcing initiatives?

The option highlighting purchasing beverages made with ethically sourced coffee is considered correct because it directly aligns with Starbucks’ commitment to ethical sourcing practices. When customers choose drinks made with coffee that is certified as ethically sourced, they are actively supporting the company's initiatives that ensure fair trade practices, environmental responsibility, and community support for coffee farmers. This choice reflects a conscious decision to contribute to sustainable sourcing and helps to drive demand for responsibly sourced products.

Engaging in options such as opting for non-dairy milk or requesting information on coffee origins may still show an interest in sustainability and its associated practices, but they do not have the same direct impact on ethical sourcing initiatives. Participating in barista training programs, while it may enhance one's knowledge of coffee preparation, is not specifically tied to engaging with the broader ethical sourcing efforts of the company in a tangible way. The focus on purchasing ethically sourced coffee makes the selected answer a more effective means of supporting Starbucks' ethical sourcing goals.