Option 1 -> A simile uses "like" or "as" to compare two things, but this sentence contains no such comparison words.
Option 2 -> Alliteration requires repetition of consonant sounds at the beginning of consecutive words, which is not present here.
Option 3 -> A pun is a play on words for humorous or rhetorical effect, which doesn't apply to this descriptive sentence.
Option 4 -> The sunset is described as "bathing" the town, which is a metaphor since light cannot literally bathe something; it's a direct comparison without using "like" or "as."
Hence, Option 4: Metaphor -> The verb "bathed" is used metaphorically to describe how the sunset's light covered and illuminated the town, creating a figurative comparison between the spreading of light and the act of bathing -> correct