Hopkin's use of "seared," "bleared," and "smeared" is an example of C) assonance.
It's not a metaphor or simile because you aren't comparing anything.
Alliteration means repetition of the same consonant in the beginning of the word, and since there are no same consonants, this isn't correct.
It would be the last option- when you want tot compare and contrast ideas
If you could insert a picture that has the full question, you could get a more reliable answer.
What type of clues are you looking for and what type of point of view do you need to have an example for? I can probably answer your question if you tell me.