Answer: B) Ethos.
Explanation: When writing, an author can use several rhetorical devices in order to persuade, inform or impact the audience in the desired way. Ethos is a commonly used rhetorical device that consists in appealing to the audience's ethics. In the given excerpt, we can see a clear example of the use of ethos (corresponding to option B) because the speaker is listing all the things she/he does in order to increase his/her credibility.