Cliff Marsden has been an audit manager at Copeland & Cahoon, CA's the past ten years. Two years ago he performed human resources and internal audit functions for 9 month: while his client underwent a major restructuring. His firm has a policy of changing audit partners and managers every five to seven years. He is reluctant to take on the audit because he believes there is an independence threat. Which threat is in play? a) integrity threat b) familiarity threat c) self-review threat d) advocacy threat