Which two of the following options do not participate in a first-party audit?

A first-party audit is an internal audit in which the organization’s own staff or contractors check the conformity and effectiveness of the ISMS. A certification body auditor and an audit team from an accreditation body are external auditors who conduct audits for the purpose of certification or accreditation. They do not participate in a first-party audit, but rather in a third-party audit. References: First & Second Party Audits - operational services, The ISO 27001 Audit Process | Blog | OneTrust, The ISO 27001 Audit Process | A Beginner’s Guide - IAS USA