Question

Which of the following is NOT an element of poetic structure?

line length
choice of subject
rhyme scheme
use of repetition

Answer 1

I would say line length. All poems have varying line length, some poems have extremely long lines while others have two word lines. The use of repetition is an element as well as rhyme scheme but is not always needed, which is why the answer would be line length and not the others. 

Answer 2

I would say line length.