Explain thoreau's figurative use of the word “burrowing” in the final paragraph. what is he digging for?

Henry David Thoreau was an American essayist, poet, philosopher, abolitionist, naturalist, tax resister, development critic, surveyor, and historian, two of his greatest works are: "Resistance to Civil Government" (also known as "Civil Disobedience") and "The Mask of Anarchy". His ideals can be summarized by this statement: “the Government should not have more power than the bestowed by its citizens”.

Henry David Thoreau was even imprisoned for refusing to pay taxes in protest for the Mexican-American War and the slavery.

Thoreau was an idealist; he opposed the oppression and tyranny from the government and I think that more people like him should exist for we need more free thinkers to defend the common citizen from the oppressive government we sometimes have.

In the first Chapter of Walden, "Economy," Thoreau explains how and why he wanted to live alone and why simplicity would help him to be more free. With less luxuries, less property, and less material things, a man is more free to do as he pleases.

this is the paragraph that you should have included from Economy:

"My instinct tells me that my head is an organ for burrowing, as some creatures use their snout and fore paws, and with it I would mine and burrow my way through these hills."

In this paragraph Thoreau uses the word Burrowing as "obtaining" or "acquiring" what he needs to live from the world and its nature. He is digging for nourishment and food, for both his body and soul. He is suggesting that we can live off from nature without depending from the social system or the government.

a, b, and c are all correct.

in june, we will have been married for eighteen months. (i am assuming this is what you want? the sentence, as you have presented it, is grammatically incorrect--   you want it corrected, yes? )