Which line in this excerpt from act IV of Shakespeare's Romeo and Juliet best reveals the dramatic irony of the scene?
NURSE: Mistress! what, mistress! Juliet! fast, I warrant her, she:
Why, lamb! why, lady! fie, you slug-a-bed!
Why, love, I say! madam! sweet-heart! why, bride!
What, not a word? you take your pennyworths now;
Sleep for a week; for the next night, I warrant,
The County Paris hath set up his rest,
That you shall rest but little. God forgive me,
Marry, and amen, how sound is she asleep!
I must needs wake her. Madam, madam, madam!
Ay, let the county take you in your bed;
He'll fright you up, i' faith. Will it not be?

(Undraws the curtains)

What, dress'd! and in your clothes! and down again!
I must needs wake you; Lady! lady! lady!
Alas, alas! Help, help! my lady's dead!
O, well-a-day, that ever I was born!
Some aqua vitae, ho! My lord! my lady!