Read the third quatrain of Shakespeare’s "Sonnet 130.” I love to hear her speak, yet well I know
That music hath a far more pleasing sound;
I grant I never saw a goddess go;
My mistress, when she walks, treads on the ground.
In order to follow the structure of a Shakespearean sonnet correctly, what must follow this quatrain?
a sestet
an octave
a fourth quatrain
a rhyming couplet