Read Shakepeare's sonnet. My mistress' eyes are nothing like the sun;
Coral is far more red than her lips' red:
If snow be white, why then her breasts are dun;
If hairs be wires, black wires grow on her head.
I have seen roses damask'd, red and white,
But no such roses see I in her cheeks;
And in some perfumes is there more delight
Than in the breath that from my mistress reeks.
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;
And yet, by heaven, I think my love as rare
As any she belied with false compare.
Which of these best describes what happens between the third quatrain and the final couplet of this sonnet?

There is a shift in tone.
There is a shift in person.
There is a shift in tense.
There is a shift in meter.