Final answer:
The Greek word "ethos" means character, which is fundamental to the concept of ethics and conveys the importance of credibility or trustworthiness in moral philosophy. The correct option is b.
Step-by-step explanation:
The Greek word "ethos" refers to character. This term lays the foundation for the concept of ethics, which concerns the moral philosophy involving systematic defense and recommendation of concepts of right and wrong behavior.
Ethos, as an ethical appeal, helps establish credibility or the trustworthiness of the speaker or authority on a given subject. This notion dates back to ancient philosophers, like Socrates, who linked the virtuous life to the knowledge of the good.
Socrates advocated that one would always choose the option that they knew to be good, thus associating ethical choices with the possession of knowledge about what goodness is. In his view, wrongdoing was a result of ignorance, and thus, the path to virtue involved education about what the good truly is.
Hence, Option b is correct.