Read this excerpt from "Ritmo/Rhythm” by Margarita Engle.

Mad and I used to do everything together,
but now I need a project all my own,
so I roam the green fields,
finding bones.

The skull of a wild boar.
The jawbone of a mule.

Which graphical element does the poet use in the excerpt?

a quatrain
right justification
three-line stanza
caesura