Why does henry david thoreau use ethos in ''resistance to civil government''?

In "Resistance to Civil Government," Henry David Thoreau uses ethos in order to help his audience gain trust in him. Thoreau uses his own personal experience in order to demonstrate his knowledge of his topic and his own personal connection to it. By using ethos in this rhetorical situation, Thoreau is attempting to inspire trust in his readers and establish his own credibility.  

The third answer is correct.