The right answer is: "The nurse does not know that Nora will leave her children, but the audience does."
When Torvald humiliates Nora, he tries to apologize with her, but she has changed, she realized her husband is a very strange man for her and in her marriage was always a doll, so she decided the only way to recognize herself is leaving from the house.
C.The characters' situation at the end is no different than at the beginning.
If there isn't room to stop, then you couldn't brake. If you want to avoid something it's unlikely that you would speed up to avoid it, so (B) - steer away - is the correct answer.