Which literary term refers to the speaker's trustworthiness and credibility?

The term that refers to the speaker's trustworthiness and credibility is ethos. Ethos is derived from the Greek word for "character," and it is one of the three modes of persuasion outlined by Aristotle, which also include logos (appeal to logic) and pathos (appeal to emotion). When a speaker demonstrates ethos, they establish their authority, moral character, and reliability in relation to the subject matter, making their argument more persuasive to the audience. Utilizing ethos effectively can help enhance the speaker's argument and foster a sense of trust between the speaker and the audience, which is essential in rhetorical situations.

Other terms listed, such as logos and pathos, focus on different aspects of persuasion; logos appeals to rational thought and logic, while pathos aims to elicit emotional responses from the audience. Pathology, on the other hand, pertains to the study of disease and is not relevant in the context of rhetorical devices. Thus, ethos is the correct choice when discussing a speaker's trustworthiness and credibility.