A. Decline the audit engagement, because the Standards prohibit internal auditors from performing engagements where they lack the necessary competencies:The Standards allow for outsourcing or co-sourcing to meet competency gaps. Declining outright is not necessary.

B. Accept the audit engagement and use the engagement as an opportunity to develop the audit team’s IT expertise while performing the audit work:This approach risks compromising audit quality as the team lacks expertise.

C. Temporarily hire an experienced and knowledgeable IT analyst from the organization's IT department to lead the audit:This could create independence issues, as the IT analyst is part of the auditee’s function.

D. Outsource the audit engagement to a reputable IT audit consulting firm:Correct. Outsourcing ensures that the engagement is performed by qualified professionals, maintaining quality and adherence to the Standards.

CIA Exam Syllabus Reference:

Domain IV: Managing the Internal Audit Function – Resourcing and Competency Management.