Why are euphemisms often used

Pls excerpted from "hope is the thing with feathers" by emily dickinson [2] and sweetest—in the gale—is heard— and sore must be the storm— that could abash the little bird that kept so many warm— [3] i've heard it in the chillest land— and on the strangest sea— yet, never, in extremity, it asked a crumb—of me. in the last stanza, the author writes that the little bird “never … asked a crumb of me.” which type of figurative language is evident in these lines? a. onomatopoeia b. alliteration c. assonance d. personification