The heroic couplet is a metric of the structure of a poem, characterized by having two verses that rhyme; in the example relief and grief are the last words of each verse and rhyme. On the other hand, each verse is made up of 5 iambs with two syllables, one accented and the other unaccented and interspersed, that is, one yes, one no, one yes and so on. So, the correct answer is C. Heroic couplet.
