Martina (a tax manager) has been assigned to the audit of Tandem Electric, Inc. Martina is concerned that Joseph, a close family friend for many years, is the CFO of Tandem Electric. Concerned about the appearance of her independence, she applies the AICPA conceptual framework and determines that the threat to her independence is significant and cannot be mitigated by safeguards. As a result, what is Martina's best course of action?