I believe the appropriate answer to be option B) the nurse's need to give up a child in order to have a job demonstrates a woman's inability to support herself.
That is only one of the moments in the play A Doll's House that develop the issue of gender inequality. The nurse has to give her child away to be able to raise someone else's child. The main character Nora finds that surprising. However, Nora herself, in order to borrow some money from the bank, has to forge her father's signature. Both women are treated as incapable and inferior, even though Nora is "superior" to the nurse when it comes to social status and money.