Which statement is the best example of an appeal to ethos? A. Imagine the joy of a dog that has spent most of its life in a small yard being allowed to run free in a huge national park. B. Dr. Mia Crawford, a board-certified cardiologist with 16 years of experience, has some strong opinions about the American diet. C. Twenty-five percent of children under the age of 12 are at risk for serious diseases such as juvenile diabetes and obesity. D. Vegetarians are 60 percent less likely to suffer from heart disease than people who eat meat.

B. Dr. Mia Crawford, a board-certified cardiologist with 16 years of experience, has some strong opinions about the American diet.

The correct answer is B: Dr. Mia Crawford, a board-certified cardiologist with 16 years of experience, has some strong opinions about the American diet.

When an author makes an appeal to ethos, he or she uses an authority to persuade the audience. For example, if I want to argue that a particular sneaker is the best one to use for running, a good appeal to ethos will use the authority of a successful track and field runner or an athlete. That's because a successful athlete, and not a chef or musician, will likely know which sneaker is the best for running.

Here, "a board-certified cardiologist with 16 years of experience" certainly has the authority to speak knowledgeably on the subject of a healthy diet. That's why B is the best answer.