The correct answer is D, specifically the part which reads "It made the slovenly wilderness." Personification is the attribution of human characteristics to something that is non-human. The word slovenly is defined as something that is messy, dirty, or careless and is usually used in reference to a person or their appearance. In this case, the author is referring to the wilderness as having the human-like quality of being slovenly.
I would say that he made an effective argument even though it was not scientifically supported. It might be considered effective because they might touch the spiritual aspect of the relationship between man and nature. He stated that trees were divine and so Americans were supposed to save them, it was a moral and ethical thing to do.
You should capitalize that.
The adverbs are resolutely, reasonalbly, truly, fiercely, only, and emphatically.