10 points
NORA. [Softly, after a pause.] It can't be. It's impossible. Itmust be
impossible! *
What is Nora in disbelief about in this line?
Torvald forced her to promise not to help Krogstad.
Torvald is angry because Nora lied about Krogstad being at the house.
Nora has finally paid the loan back in full.
Torvald has told Nora that lying mothers corrupt their children morally.

I believe the answer you're looking for is D.

Explanation:

you could come to this conclusion because after reading this mind and adults house she says..

NORA. [Softly, after a pause.] It can't be. It's impossible. It

must be impossible!

ANNA. [At the door, left.] The little ones are begging so prettily

to come to mamma.

NORA. No, no, no; don't let them come to me! Keep them with you,

Anna.

ANNA. Very well, ma'am. [Shuts the door.

NORA. [Pale with terror.] Corrupt my children!- Poison my home!

[Short pause. She throws back her head.] It's not true! It can

never, never be true!