Answer:
B. He disagreed with the idea of it.
Step-by-step explanation:
Henry David Thoreau's essay "Civil Disobedience" focuses on the importance of individualism and the need for an individual to prioritize his rights and concerns instead of what the law dictates. He also propounds the importance of following one's conscience and not blindly obey the government and their 'laws'.
And in this regard, he also refuses to pay the poll tax because he disagreed with the idea. This was because this tax that the government collects from the Americans is used to 'support' the Mexican war. So, if the people pay taxes, then this money is used to help the armies in the war, thus making the people indirect supporters of the war. And those who 'criticize' and condemn the war must make a point not to 'support' it by refusing to pay the taxes. This is also his reason to not pay taxes as he disagreed with it.