Which device does the poet use by ending every second and fourth line with similar-sounding words?

The answer is C: Rhyme.

The one device that is most commonly associated with poetry by the general public is the Rhyme Scheme or simply, Rhyme. It uses words with different beginning sounds but whose endings sound alike, including the final vowel sound and everything following it. It is applied in an alternating method which in a stanza, follows mostly this format: a-b-a-b where the first and third line rhyme, while the second and fourth line rhyme.