In walden, thoreau writes, “love your life, poor as it is.” this is an example of the writer’s tone.

a. philosophical
b. formal
c. conversational
d. metaphorical

A. philosophical

Explanation:

It isn't really formal. It has nothing to indicate formality or a conversation in the sentence. It can't really be metaphorical since there's no sign of figurative language either. It seems to be an idea of how the life must be appreciated. A lesson, maybe.

One of the definitions of philosophical is: "having or showing a calm attitude toward disappointments or difficulties."

this seems to fit quite well