<span>B. We were walking by the lake when we heard a siren.
C. By the time I graduated, I had attended three different high schools.
D. Though he had been rude at first, Rupert eventually won over the congregation
These three sentences are all correct, because even if the verb tense shifts it still makes sense within the context of the situation.</span>
Answer:
night
Explanation:
given that the poet is saying "the sun has<em> long been set</em>" it means that the sun has not just set, but it has been set for a long while, meaning it is nighttime
