A is the fragment. "Because...night" is not a sentence. It is a dependent clause. You can attach it to a predicate and explain what happened when he walked at night, but the predicate isn't given. Since you only have an independent cause, which is given away by the word because, this is a fragment. B, C, and D have subject, verb, AND predicate/no dependent clause. You have to have a dependent clause (a fragment sentence) attached to an independent (an actual sentence). I know this is lengthy but I hope it helps.
The line has the /w/ sound repeated three times. Alliteration is the repetition of the same sound within a group of words. A simile is a comparison using like or as. The line does not have either like or as. An echo is when the end of a line or stanza is repeated like an echo. This is not the case either. The line also does not have personification (the giving of human-like traits to a non-human thing).
<span>Robert Stawell Ball develops the central idea by providing biographical information and the discoveries by specific astronomers to his book. Thank you for posting your question. I hope this answer helped you. Let me know if you need more help. </span>