Allusion is the literary element that is present in this line from Walden by Henry David Thoreau.
Allusion is a brief and indirect reference to a person, place, thing or idea of historical, cultural, literary or political significance. It does not describe in detail the person or thing to which it refers.
The correct answer between all the choices given is the second choice or letter B. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.