What is the effect of enjambment in this excerpt from "Porphyria's Lover" by Robert Browning?

That moment she was mine, mine, fair,
Perfectly pure and good: I found
A thing to do, and all her hair
In one long yellow string I wound
Three times her little throat around,
And strangled her. No pain felt she;





A. It conveys pain.



B. It enhances the shocking effect.



C. It introduces a pause.