Which of the Following Describes the Purpose of Henry David

Which of the following describes the purpose of Henry David Thoreau's book Walden?

A) It was written to document Thoreau's spiritual search for meaning beyond the artificiality of "civilized" life.
B) It was intended to serve as a guidebook for others who wanted to learn how to survive alone in the woods.
C) The book sought to advise farmers on practical matters that would increase the profitability of small farms.
D) It warned of the dangers that could arise from too many efforts to promote and create social reform.