[Carter's Financials] Kayla Works as an Accountant

[Carter's financials] Kayla works as an accountant. Rudy, an attorney, is working on a case for Carter, who is suing his business partner. Rudy does not have the time or the background to perform a complete analysis of Carter's financial statements, so Rudy asks Kayla to meet with Carter and assist Rudy with interpreting Carter's financial statements. Kayla meets with Carter, who provides a lengthy explanation of the financial statements and facts of the case. Afterwards, she prepares a memorandum for Rudy outlining her analysis of the financial issues of the case. Kayla runs into Carter at a baseball game several months later. Carter tells her that the stress is getting to him and he wants to move to Florida because he can no longer tolerate his business partner. A year later, at trial, Kayla is called as a witness by Carter's business partner to testify against Carter. No accountant-client privilege exists in Kayla's state, which is also where the trial takes place.
-If Kayla is called to testify at trial, what is her best argument against revealing information about Carter's financial statements?

A) Confidential working papers are always protected under state or federal law.
B) Ethically, Kayla has a duty to keep the information confidential in order to not breach state laws on malpractice.
C) Kayla could claim the attorney-client privilege.
D) Accountant-client privilege does not exist in her state but federal law recognizes it and would protect her.
E) State law would protect Kayla from malpractice and thus she would have to testify.