The correct answers are:
1- Henry David Thoreau (D)
Thoreau was a leading transcendalist and was known for his book "Walden." This was a journal in which he reflected upon living in natural surroundings.
2- Walt Whitman (F)
Whitman was widely considered the American father of free verse. This style refers to leaving behind the traditional meter for poems, and used a more irregular one.
3- Nathaniel Hawthorne (A)
This passage belongs to the short story "Young Goodman Brown," one of Hawthorne's short stories, which was published in 1835.