Read the following passage from "civil disobedience" by henry david thoreau:

a wise man will not leave the right to the mercy of chance, nor wish it to prevail through the power of the majority. there is but little virtue in the action of masses of men. when the majority shall at length vote for the abolition of slavery, it will be because they are indifferent to slavery, or because there is but little slavery left to be abolished by their vote. they will then be the only slaves. only his vote can hasten the abolition of slavery who asserts his own freedom by his vote.
how does thoreau use logos in this passage?
a. to provide factual evidence that his claims are trustworthy
b. to evoke in readers the negative feelings associated with slavery
c. to establish his credibility by relating his expertise on the subject
d. to demonstrate the soundness of his argument through analogy