Hi guys please help me with this :)

Answer:
Rhythm
Explanation:
I believe that the question is asking about the poetic devices(?)
So in 'Nothing Gold Can Stay' its predominantly iambic in rhythm, by that I mean there are 3 regular stress beats to most of the lines, aside from lines 1 and 8, which contain trochees and spondees: 'Nature's first green is gold, Nothing gold can stay'