Thorp, CPA, was engaged to prepare tax returns and provide other tax services to Ivor Co. During the engagement, Thorp discovered that Ivor was selling worthless mortgages to investors. Ivor was indicted and Thorp was subpoenaed to testify at the criminal trial. Ivor claimed accountant-client privilege to prevent Thorp from testifying. Which of the following statements is true regarding Ivor's claim?

A. Ivor can claim an accountant-client privilege only in states that have enacted a statute creating such a privilege.
B. Ivor can claim an accountant-client privilege only in federal courts.
C. The accountant-client privilege can be claimed only in civil suits.
D. The accountant-client privilege can be claimed only to limit testimony to audit subject matter.