When a performer departs significantly from a poem's written structure, what argument are they making?

When a performer departs significantly from a poem's written structure, what argument are they making?
a.
That the audience should ignore the actual meaning of the words
b.
That the poet failed to make sufficiently clear choices on the page
c.
That the written form is the most authoritative version of the poem
d.
That their reading unlocks something the written structure cannot