the grim outlook of the late Victorian era
I believe it would be declarative because it is stating a fact.
Interrogative is a question and will allmost always end in a question marks.
Imperative is an order and will almost always end in a period.
Exclamatory shows excitement or concern ends most often with a exclamation mark.
You would have to tell us what the sketches are
The correct answer should be "it forces the reader to pause, emphasizing the calm of the snow." because the tone of the poem is peaceful and content, not choppy and nervous